bluuebunny/crossref_metadata_2025 huggingface dataset:
RESPONSE OF ANABAENA FLOS‐AQUAE (CYANOPHYTA) NITROGENASE ACTIVITY TO SUDDEN PHOSPHATE DEPRIVATION1
Authors: Gerber Brain L. , Wickstrom Conrad E.
Published: October 2004

Cultures of Anabaena flos‐aquae (Lyng.) Breb. Were used to determine changes in nitrogenase activity (acetylene reduction) after external concentrations of phosphorus were lowered. Two days following immersion in phosphorus‐free medium, nitrogenase activity (NA) had doubled and required 8 days to return to time zero levels. Subsequent long‐term experiments showed that concentrations of soluble reactive phosphorus (SRP) released from the algae transferred into the –P medium reached maximum levels by day 3 and returned to initial low values by days 7–10. NA was always highest during this SRP release‐reassimilation phase but steadily decreased after reassimilation was complete. Day 56 NA was 5–14% of initial activity. The data support the hypothesis that heterocyst and vegetative cell ATP pools are discrete and suggest that the short‐term effects of phosphorus removal as an aquatic restoration technique need further study.
DEVELOPMENTAL STUDIES IN PORPHYRA (RHODOPHYCEAE). III. EFFECT OF CULTURE CONDITIONS ON WALL REGENERATION AND DIFFERENTIATION OF PROTOPLASTS1
Authors: Polne‐Fuller Miriam , Gibor Aharon
Published: October 2004

Protoplasts isolated from thalli of four Porphyra species regenerated successfully into differentiated plantlets. The efficiency of protoplast isolation and the developmental patterns of the regenerating protoplasts depended on the type of tissues from which they were isolated. However, culture conditions greatly influenced the patterns of development at the cellular and organismal levels. Sorbitol, nitrogen, and agar concentration in the medium controlled rates of cell division, thickening of cell walls, development of rhizoids, and formation of calluses or differentiated blades. Agitation disturbed the attachment of the protoplasts to a substrate. Cells in agitated cultures produced suspensions of single cells and non‐polarized small calluses. Calluses which developed from protoplasts survived in storage for over two years. The stored calluses, and cells and protoplasts that were isolated from them, were subcultured successfully. We forsee extensive use of Porphyra cell suspensions for strain selection and vegetative propagation of cultivars. This technology, which makes vegetative cloning of selected Porphyra plants possible, may eliminate the need for cultivation and storage of the conchocelis phase. Protoplasts are also being used as tools for studies in genetic engineering of these commercial species.
PHYLOGENY OF CHLAMYDOMONAS (CHLOROPHYTA) BASED ON CLADISTIC ANALYSIS OF NUCLEAR 18S rRNA SEQUENCE DATA1
Authors: Buchheim Mark A. , Turmel Monique , Zimmer Elizabeth A. , Chapman Russell L.
Published: October 2004

The genus Chlamydomonas Ehrenberg may contain as many as 450 described species. Morphological, physiological and molecular data show that variation among some Chlamydomonas species can he great, leading to speculation that multiple, generic‐level lineages exist within this genus. The most recent systematic studies of Chlamydomonas have led to proposals of nine distinct morphological and 15 distinct sporangial autolysin groups. Partial sequences from the nuclear small subunit rRNAs from 14 Chlamydomonas species representing 12 autolysin and four morphological groups, and from three flagellates thought to he related to Chlamydomonas were determined in a phylogenetic study of relationships among these algae. Sequence comparisons among some Chlamydomonas species revealed differences comparable to the sequence divergence between soybeans and cycads. Cladistic analysis of the sequence data suggests that multiple lineages exist among species of Chlamydomonas. Some of these lineages represent alliances of both Chlamydomonas and non‐Chlamydomonas taxa; thus, the current taxonomy does not reflect natural, or monophyletic, groups. Collectively, these lineages may represent distinct families or even orders.
THE PLEURASTROPHYCEAE AND MICROMONADOPHYCEAE: A CLADISTIC ANALYSIS OF NUCLEAR rRNA SEQUENCE DATA1
Authors: Kantz Thomas S. , Theriot Edward C. , Zimmer Elizabeth A. , Chapman Russell L.
Published: October 2004

Partial sequences from the nuclear‐encoded 18S and 26S ribosomal RNA molecules from representatives of the five classes of Chlorophyta sensu Mattox and Stewart (1984) were analyzed cladistically in a study of the phylogenetic relationships among the Micromonadophyceae, Pleurastrophyceae, and other green algae. The sequence data indicate that the Micromonadophyceae (= Prasinophyceae) is not monophyletic but comprises at least three lineages occupying a basal position among the green algae. Though the Pleurastrophyceae and the Ulvophyceae both possess counter‐clockwise basal body orientations, the sequence data indicate that the Pleurastrophyceae is the sister group to the Chlorophyceae. The molecular data alone do not resolve the monophyly of the Pleurastrophyceae or the Ulvophyceae; however, a combined data set of molecular and non‐molecular characters support a monophyletic Pleurastrophyceae. Analyses with user‐defined tree topologies and the bootstrap method of character resampling indicate that the relationships shown in the most parasimonious cladograms are well supported by the character data.
We Can Work It Out: The Impact of Technological Change on the Demand for Low‐Skill Workers
Authors: Manning Alan
Published: October 2004

There is little doubt that technology has had the most profound effect on altering the tasks that we humans do in our jobs. Economists have long speculated on how technical change affects both the absolute demand for labour as a whole and the relative demands for different types of labour. In recent years, the idea of skill‐biased technical change has become the consensus view about the current impact of technology on labour demand, namely that technical change leads to an increase in the demand for skilled relative to unskilled labour painting a bleak future for the employment prospects of less‐skilled workers. But, drawing on a recent paper by Autor, Levy and Murnane (2003) about the impact of technology on the demand for different types of skills, this paper argues that the demand in the least‐skilled jobs may be growing. But, it is argued that employment of the less‐skilled is increasingly dependent on physical proximity to the more‐skilled and may also be vulnerable in the long‐run to further technological developments.
Understanding Mexican‐American Marriage Patterns Using a Life‐Course Approach*
Authors: Kelly Raley R. , Elizabeth Durden T. , Wildsmith Elizabeth
Published: October 2004

Objective. Guided by a life‐course framework that incorporates the interconnection between marriage, migration, and other transitions, we critically examine the familism explanation for the earlier age at marriage among Mexican Americans.

Methods. We compare the marriage patterns of Mexican immigrants derived from the National Survey of Family Growth (NSFG) to those of women living in Mexico derived from the Mexican Census. We then use data from the NSFG to estimate proportional hazard models of marriage using fixed variables such as parent's education and time‐varying variables such as school enrollment.

Results. Analyses show that the Mexican immigrant population marries earlier than Mexicans who do not migrate to the United States. In addition, the U.S.‐born Mexican population has lower marriage rates than whites once family background characteristics associated with early marriage are controlled and Anglos are no less likely than Mexican Americans to marry in response to a pregnancy.

Conclusion. We find reason to doubt that ethnic differentials are driven by a strong attachment to marriage, female chastity, and the “traditional” family. Although cultural factors may play an important role, researchers need to more carefully specify the aspects of Mexican culture that might encourage marriage and how these factors interrelate with economic and demographic constraints.
Clostridial infection in a liver transplant recipient
Authors: Solis Diego R , Hemming Alan W , Reed Alan , Van der Werf Willem J , Fujita Shiro , Howard Richard J
Published: October 2004

Abstract: Clostridium perfringensinfection in a liver transplant recipientis a rare complication. We report a case of a liver allograft gas gangrene. The case illustrates the fulminant and rapidly devastating course of this complication.
Initial experience using histidine‐tryptophan‐ketoglutarate solution in clinical pancreas transplantation*
Authors: Potdar Santosh , Malek Sayeed , Eghtesad Bijan , Shapiro Ron , Basu Amit , Patel Kusum , Broznick Brian , Fung John
Published: October 2004

Abstract:  Background:  The colloid‐based University of Wisconsin (UW) preservation solution has been used extensively in clinical pancreas transplantation. Experimental studies support the use of the crystalloid‐based histidine‐tryptophan‐ketoglutarate (HTK) preservation solution for this purpose.

Aim:  We report our initial experience with HTK for pancreas allograft preservation and compare this to a contemporary experience with UW solution in conventional multiorgan deceased donors (<50 yr).

Materials and methods:  Retrospectively collected information on 33 pancreas transplants between September 2001 and October 2002 were analyzed for early graft function and complications up to 30 d after procurement and storage in either HTK or UW solutions. During multi‐organ recovery, either UW solution (4–5 L) or HTK solution (8–10 L) was used for aortic perfusion and subsequent back‐table flush and storage. Exocrine drainage of 31 pancreas allografts was enteric, while the bladder was used for drainage in two cases. Patient outcomes were analyzed according to the preservation solution used. Sixteen pancreata were used in combination with a kidney allograft (SPK), seven were used in patients after prior kidney transplantation (PAK), while 10 were used in patients who were not in renal failure (PTA).

Results:  The UW group consisted of 17 patients (10 SPK, three PAK, four PTA) with a mean donor age of 29.5 ± 10.7, and a mean cold ischemia time of 15.1 ± 2.1 h. The mean post‐transplant pancreas and kidney function on days 1 and 10 were amylase (315 and 99 IU/L), lipase (1727 and 346 IU/L), glucose (121 and 100 mg/dL) and creatinine (5.01 and 1.77 mg/dL). Patient and graft survival was 100% at 1‐month post transplant.

In the HTK group there were 16 patients (six SPK, four PAK, six PTA) with a mean donor age 21.9 ± 5.7 and a mean cold ischemia time 14.0 ± 1.3 h. The mean post‐transplant pancreas and kidney function on days 1 and 10 were amylase (588 and 126 IU/L), lipase (4711 and 441 IU/L), glucose (97 and 109 mg/dL) and creatinine (5.28 and 2.42 mg/dL). Patient survival was 100% while graft survival was 94% at 1‐month post‐transplant.

Conclusions:  Early graft function and complications are comparable with HTK and UW solutions for pancreas allograft preservation.
Improving exercise capacity, 6 wk training tends to reduce circulating endothelin after heart transplantation
Authors: Doutreleau Stèphane , Piquard François , Lonsdorfer Evelyne , Rouyer Olivier , Lampert Eliane , Mettauer Bertrand , Richard Ruddy , Geny Bernard
Published: October 2004

Abstract:  Short‐term survival is no longer the pivotal issue after heart transplantation but, most heart‐transplant (Htx) patients still present with increased circulating endothelin‐1 (ET) and reduced exercise capacity. ET‐1 limits both exercise‐induced vasodilation and blood flow redistribution toward acting muscles and might be accessible to training. This study was performed to investigate the effect of training on ET‐1 and whether an eventual training‐induced improvement in exercise capacity may be related to reduced baseline or exercise circulating ET‐1 in Htx patients. Five Htx patients performed a maximal bicycle exercise test and an endurance exercise test before and after a training program of 18 exercises sessions during 6 wk. ET‐1 was determined by radioimmunoassay at rest, end endurance exercise and 30 min recovery, before and after training. Training improved significantly Htx's maximal oxygen uptake (+13.1 ± 4.8%; p < 0.05) and also reduced significantly the endurance exercise‐induced heart rate increase. Resting ET‐1 was increased in Htx (5.98 ± 1.88 vs. 1.61 ± 0.25 pmol/L in controls; p < 0.01) but although ET‐1 modulation might participate in training‐induced beneficial effects, training failed to modulate either resting or exercise ET‐1 plasma level. Training‐induced improvement in exercise capacity might not mainly due to decreased ET‐1 after heart transplantation. Further supporting the usefulness of training, these preliminary data suggest that improved exercise capacity may not be mainly due to decreased ET‐1 in Htx patients. Further, larger scale studies will be needed to investigate whether an impaired nitric oxide pathway stimulation might explain such results and whether a longer training program can reduce local ET‐1, arising from working muscles after heart transplantation.
Identical reconstitution after bone marrow transplantation in twins who received fresh and cryopreserved grafts harvested at the same time from their older brother
Authors: Shinkoda Yuichi , Ijichi Osamu , Tanabe Takayuki , Ishikawa Shuji , Kamitamari Akira , Nishikawa Takuroh , Ikarimoto Naoaki , Kawano Yoshifumi
Published: October 2004

Abstract:  We report here the reconstitution after bone marrow transplantation (BMT) in identical infant twins with acute myelogenous leukemia (AML). They were diagnosed at 8 and 9 months of age. Complete remission was induced after two courses of chemotherapy. After four and five courses of chemotherapy, respectively, they received BMT at 2‐month interval from the same HLA‐identical older brother. The total dose of marrow nucleated cells (NC) harvested was 77.7 × 108. The first patient was transplanted with half of the total dose of NC. The remaining cells were cryopreserved without the use of a programmed freezer and transplanted into the second patient 2 months later. The number of days for neutrophil (>0.5 × 109/L), platelet (>50 × 109/L), and reticulocyte (>1%) recovery were, respectively, 15, 21, and 14 in the first case and 12, 21, and 15 in the second case. The clinical courses after BMT were uneventful in both cases, except for mild acute GVHD, and complete remission has been maintained >4 yr with full recovery of immune and marrow function. Based on the results in these cases, we confirmed that marrow cells that have been cryopreserved without the use of a programmed freezer could reconstitute immune and marrow function as well as non‐cryopreserved cells.
West Nile virus encephalitis: an emerging disease in renal transplant recipients
Authors: Wadei Hani , Alangaden George J , Sillix Dale H , El‐Amm Jose M , Gruber Scott A , West Miguel S , Granger Darla K , Garnick James , Chandrasekar Pranatharthi , Migdal Stephen D , Haririan Abdolreza
Published: October 2004

Abstract:  West Nile virus (WNV) has emerged as an important cause of several outbreaks of febrile illness and encephalitis in North America over the past few years. The most common manifestation in symptomatic patients is a transient febrile illness. Neuroinvasive disease, that can be fatal, occurs most often in elderly and immunocompromised hosts. The role of this virus as a cause of meninoencephalitis in organ transplant recipients is becoming better recognized. We describe herein the clinical course of two renal allograft recipients who developed WNV encephalitis. One patient developed status epilepticus and eventually died, while the other had a full recovery. In both cases, the diagnosis was confirmed by detection of WNV‐specific IgM in CSF or serum, with a delayed antibody response in one patient. This viral infection should be considered in all renal transplant recipients who present with a febrile illness associated with neurological symptoms.
Knowledge and opinions about organ donation and transplantation among Vietnamese Americans in Seattle, Washington: a pilot study
Authors: Pham Hien , Spigner Clarence
Published: October 2004

Abstract:  Background:  Racial/ethnic minorities comprise almost 50% of registrants on national waiting lists for organ transplantation in the USA. As the list continues to expand, organ shortage becomes a bigger problem. Increasing donation rates especially among racial minority groups would lower the waiting times for these groups.

Purpose:  Asian Americans are among the fastest growing and most diverse ethnic group in the USA, but research on their knowledge or opinions about organ donation is rare.

Population:  A non‐random sample of 350 Vietnamese American church attendees and students attending a major university in Seattle (Washington), was drawn.

Methods:  A self‐administered 39‐item knowledge/opinion‐based survey was conducted during June to August 2003.

Results:  Of 278 respondents (a 79.7% response rate), 69.1% knew blood‐type made a difference in donation (p = 0.000), 61.6% knew transplant survival rates were high (p = 0.000), and 75.9% knew transplants could come from living donors (p = 0.000). But 53.4% also thought organs could be sold for money in the USA (p = 0.000), and 49.8% thought more people died of auto accidents and gunshot wounds than from heart disease (p = 0.000). Those who answered correctly to more than 50% of the knowledge questions were also more likely to favor donation (p = 0.007).

Conclusion:  We found among this study population that having correct knowledge about organ donation related to a willingness to donate.
Psychological effects of living related kidney transplantation – risks and chances
Authors: Heck Gretel , Schweitzer Jochen , Seidel‐Wiesel Maria
Published: October 2004

Abstract:  Background:  Recipients of living donor kidney transplantation hope for an improved physical well‐being after transplant. Furthermore the patients and their relatives frequently expect an improvement in their psychological findings in consequence of the living related transplantation. The present study examines the psychosocial effects of living donor kidney transplantation for donors and recipients under successful as well as complicated circumstances.

Material and methods:  Based on 31 catamnestic interviews of recipient–donor couples and a content analysis of these interviews, hypotheses regarding the psychological requirements for a successful progression of a living kidney donation are deduced and put forward.

Results:  The aspiration for an improvement of psychological problems, particularly anxiety and depression, as an effect of transplantation can on the basis of the present results not be supported. Living donor kidney transplantation between close recipient and donors must not be regarded as a means to solve psychological problems and familial conflicts. An attitude characterized by realistic and modest expectations as well as relationships, which have been cleared of extreme conflicts prior to the transplantation could facilitate a favourable psychological progression.
Post‐transplant C‐reactive protein monitoring can predict chronic allograft nephropathy
Authors: Sezer Siren , Akcay Ali , Ozdemir Fatma Nurhan , Kulah Eyup , Arat Zubeyde , Haberal Mehmet
Published: October 2004

Abstract:  Chronic allograft nephropathy (CAN) is a major problem after renal transplantation and chronic inflammation can be one of its promoters. C‐reactive protein (CRP) is an important marker of inflammation and atherosclerosis. We retrospectively analyzed the predictive role of serum CRP levels on the development of CAN and graft failure. One hundred and twenty‐five renal transplant patients were randomly included into the study. Serum CRP levels were measured at pre‐transplant period, first month after transplantation and at yearly intervals throughout follow‐up. CAN was diagnosed in 40.8% of patients and 82.4% of them had graft failure in 60.9 ± 36.7 months. There was no difference at pre‐transplant CRP levels of patients with and without CAN, but the first month CRP levels were higher in those who experienced CAN. The initial 3‐yr mean CRP levels were higher, but not statistically different between the patients with and without CAN. The simultaneously detected CRP levels when CAN were diagnosed was significantly higher in those with CAN. High post‐transplant CRP levels at the first month and at the diagnosis of CAN significantly influenced the allograft failure according to the regression analysis. CRP monitoring gives important information about the risk for CAN and graft failure. Therefore, CRP levels should be included in the follow‐up data after renal transplantation.
Campath and renal transplant rejection
Authors: Thomas Philip G , Ishihara Kanae , Vaidya Smita , Gugliuzza Kristene K
Published: October 2004

Abstract:  No clear guidelines exist for the treatment of acute vascular rejection following renal transplantation. This report documents one patient who was treated with plasmapheresis, immunoglobulin and Campath with good initial response. However, rejection recurred resulting in graft loss and, in addition, the patient developed post‐transplant lymphoma.
A novel pathway for sequential transformation of 7‐dehydrocholesterol and expression of the P450scc system in mammalian skin
Authors: Slominski Andrzej , Zjawiony Jordan , Wortsman Jacobo , Semak Igor , Stewart Jeremy , Pisarchik Alexander , Sweatman Trevor , Marcos Josep , Dunbar Chuck , C. Tuckey Robert
Published: October 2004

Following up on our previous findings that the skin possesses steroidogenic activity from progesterone, we now show widespread cutaneous expression of the full cytochrome P450 side‐chain cleavage (P450scc) system required for the intracellular catalytic production of pregnenolone, i.e. the genes and proteins for P450scc enzyme, adrenodoxin, adrenodoxin reductase and MLN64. Functionality of the system was confirmed in mitochondria from skin cells. Moreover, purified mammalian P450scc enzyme and, most importantly, mitochondria isolated from placenta and adrenals produced robust transformation of 7‐dehydrocholesterol (7‐DHC; precursor to cholesterol and vitamin D3) to 7‐dehydropregnenolone (7‐DHP). Product identity was confirmed by comparison with the chemically synthesized standard and chromatographic, MS and NMR analyses. Reaction kinetics for the conversion of 7‐DHC into 7‐DHP were similar to those for cholesterol conversion into pregnenolone. Thus, 7‐DHC can form 7‐DHP through P450scc side‐chain cleavage, which may serve as a substrate for further conversions into hydroxy derivatives through existing steroidogenic enzymes. In the skin, 5,7‐steroidal dienes (7‐DHP and its hydroxy derivatives), whether synthesized locally or delivered by the circulation, may undergo UVB‐induced intramolecular rearrangements to vitamin D3‐like derivatives. This novel pathway has the potential to generate a variety of molecules depending on local steroidogenic activity and access to UVB.
Mimicking phosphorylation of the small heat‐shock protein αB‐crystallin recruits the F‐box protein FBX4 to nuclear SC35 speckles
Authors: den Engelsman John , Bennink Erik J. , Doerwald Linda , Onnekink Carla , Wunderink Lisa , Andley Usha P. , Kato Kanefusa , de Jong Wilfried W. , Boelens Wilbert C.
Published: October 2004

The mammalian small heat shock protein αB‐crystallin can be phosphorylated at three different sites, Ser19, Ser45 and Ser59. We compared the intracellular distribution of wild‐type, nonphosphorylatable and all possible pseudophosphorylation mutants of αB‐crystallin by immunoblot and immunocytochemical analyses of stable and transiently transfected cells. We observed that pseudophosphorylation at two (especially S19D/S45D) or all three (S19D/S45D/S59D) sites induced the partial translocation of αB‐crystallin from the detergent‐soluble to the detergent‐insoluble fraction. Double immunofluorescence studies showed that the pseudophosphorylation mutants localized in nuclear speckles containing the splicing factor SC35. The αB‐crystallin mutants in these speckles were resistant to mild detergent treatment, and also to DNase I or RNase A digestion, indicating a stable interaction with one or more speckle proteins, not dependent on intact DNA or RNA. We further found that FBX4, an adaptor protein of the ubiquitin‐protein isopeptide ligase SKP1/CUL1/F‐box known to interact with pseudophosphorylated αB‐crystallin, was also recruited to SC35 speckles when cotransfected with the pseudophosphorylation mutants. Because SC35 speckles also react with an antibody against αB‐crystallin endogenously phosphorylated at Ser45, our findings suggest that αB‐crystallin has a phosphorylation‐dependent role in the ubiquitination of a component of SC35 speckles.
Folding of epidermal growth factor‐like repeats from human tenascin studied through a sequence frame‐shift approach
Authors: Zanuttin Francesco , Guarnaccia Corrado , Pintar Alessandro , Pongor Sándor
Published: October 2004

In order to investigate the factors that determine the correct folding of epidermal growth factor‐like (EGF) repeats within a multidomain protein, we prepared a series of six peptides that, taken together, span the sequence of two EGF repeats of human tenascin, a large protein from the extracellular matrix. The peptides were selected by sliding a window of the average length of tenascin EGF repeats over the sequence of EGF repeats 13 and 14. We thus obtained six peptides, EGF‐f1 to EGF‐f6, that are 33 residues long, contain six cysteines each, and bear a partial overlap in the sequence. While EGF‐f1 corresponds to the native EGF‐14 repeat, the others are frame‐shifted EGF repeats. We carried out the oxidative folding of these peptides in vitro, analyzed the reaction mixtures by acid trapping followed by LC‐MS, and isolated some of the resulting products. The oxidative folding of the native EGF‐14 peptide is fast, produces a single three‐disulfide species with an EGF‐like disulfide topology and a marked difference in the RP‐HPLC retention time compared with the starting product. On the contrary, frame‐shifted peptides fold more slowly and give mixtures of three‐disulfide species displaying RP‐HPLC retention times that are closer to those of the reduced peptides. In contrast to the native EGF‐14, the three‐disulfide products that could be isolated are mainly unstructured, as determined by CD and NMR spectroscopy. We conclude that both kinetics and thermodynamics drive the correct pairing of cysteines, and speculate about how cysteine mispairing could trigger disulfide reshuffling in vivo.
The N‐linked oligosaccharides of aminopeptidase N from Manduca sexta
Authors: Stephens Elaine , Sugars Jane , Maslen Sarah L. , Williams Dudley H. , Packman Len C. , Ellar David J.
Published: October 2004

Mass spectrometric studies on the N‐linked glycans of aminopeptidase 1 from Manduca sexta have revealed unusual structures not previously observed on any insect glycoprotein. Structure elucidation of these oligosaccharides was carried out by high‐energy collision‐induced dissociation (CID) using a matrix‐assisted laser desorption/ionization time‐of‐flight/time‐of‐flight (MALDI‐TOF/TOF) tandem mass spectrometer. These key experiments revealed that three out of the four N‐linked glycosylation sites in this protein (Asn295, Asn623 and Asn752) are occupied with highly fucosylated N‐glycans that possess unusual difucosylated cores. Cross‐ring fragment ions and ‘internal’ fragment ions observed in the CID spectra, showed that these fucoses are found at the 3‐position of proximal GlcNAc and at the 3‐position of distal GlcNAc in the chitobiose unit. The latter substitution has only been previously observed in nematodes. In addition, these core structures can be decorated with novel fucosylated antennae composed of Fucα(1‐3)GlcNAc. Key fragment ions revealed that these antennae are predominantly found on the upper 6‐arm of the core mannose. The paucimannosidic N‐glycan (Man3GlcNAc2), commonly found on other insect glycoproteins, is the predominant oligosaccharide found at the remaining N‐glycosylation site (Asn609).
Allosteric water and phosphate effects in Hoplosternum littorale hemoglobins
Authors: Peres Patricia , de Azevedo Júnior Walter F. , Bonilla‐Rodriguez Gustavo O.
Published: October 2004

This paper reports the results obtained using the osmotic stress method applied to the purified cathodic and anodic hemoglobins (Hbs) from the catfish Hoplosternum littorale, a species that displays facultative accessorial air oxygenation. We demonstrate that water potential affects the oxygen affinity of H. littorale Hbs in the presence of an inert solute (sucrose). Oxygen affinity increases when water activity increases, indicating that water molecules stabilize the high‐affinity state of the Hb. This effect is the same as that observed in tetrameric vertebrate Hbs. We show that both anodic and cathodic Hbs show conformational substrates similar to other vertebrate Hbs. For both Hbs, addition of anionic effectors, especially chloride, strongly increases the number of water molecules bound, although anodic Hb did not exhibit sensitivity to saturating levels of ATP. Accordingly, for both Hbs, we propose that the deoxy conformations coexist in at least two anion‐dependent allosteric states, To and Tx, as occurs for human Hb. We found a single phosphate binding site for the cathodic Hb.
Reformable intramolecular cross‐linking of the N‐terminal domain of heparin cofactor II
Authors: Brinkmeyer Stephan , Eckert Ralf , Ragg Hermann
Published: October 2004

The crystal structure of a heparin cofactor II (HCII)–thrombin Michaelis complex has revealed extensive contacts encompassing the N‐terminal domain of HCII and exosite I of the proteinase. In contrast, the location of the N‐terminal extension in the uncomplexed inhibitor was unclear. Using a disulfide cross‐linking strategy, we demonstrate that at least three different sites (positions 52, 54 and 68) within the N terminus may be tethered in a reformable manner to position 195 in the loop region between helix D and strand s2A of the HCII molecule, suggesting that the N‐terminal domain may interact with the inhibitor scaffold in a permissive manner. Cross‐linking of the N terminus to the HCII body does not strongly affect the inhibition of α‐chymotrypsin, indicating that the reactive site loop sequences of the engineered inhibitor variants, required for interaction with one of the HCII target enzymes, are normally accessible. In contrast, intramolecular tethering of the N‐terminal extension results in a drastic decrease of α‐thrombin inhibitory activity, both in the presence and in the absence of glycosaminoglycans. Treatment with dithiothreitol and iodoacetamide restores activity towards α‐thrombin, suggesting that release of the N terminus of HCII is an important component of the multistep interaction between the inhibitor and α‐thrombin.
Coexpression, purification and characterization of the E and S subunits of coenzyme B12 and B6 dependent Clostridium sticklandiid‐ornithine aminomutase inEscherichia coli
Authors: Chen Hao‐Ping , Hsui Fang‐Ciao , Lin Li‐Ying , Ren Chien‐Tai , Wu Shih‐Hsiung
Published: October 2004

d‐Ornithine aminomutase from Clostridium sticklandii comprises two strongly associating subunits, OraS and OraE, with molecular masses of 12 800 and 82 900 Da. Previous studies have shown that in Escherichia coli the recombinant OraS protein is synthesized in the soluble form and OraE as inclusion bodies. Refolding experiments also indicate that the interactions between OraS and OraE and the binding of either pyridoxal phosphate (PLP) or adenosylcobalamin (AdoCbl) play important roles in the refolding process. In this study, the DNA fragment containing both genes was cloned into the same expression vector and coexpression of the oraE and oraS genes was carried out in E. coli. The solubility of the coexpressed OraS and OraE increases with decreasing isopropyl thio‐β‐d‐galactoside induction temperature. Among substrate analogues tested, only 2,4‐diamino‐n‐butyric acid displays competitive inhibition of the enzyme with a Ki of 96 ± 14 µm. Lys629 is responsible for the binding of PLP. The apparent Kd for coenzyme B6 binding to d‐ornithine aminomutase is 224 ± 41 nm as measured by equilibrium dialysis. The mutant protein, OraSE–K629M, is successfully expressed. It is catalytically inactive and unable to bind PLP. Because no coenzyme is involved in protein folding during in vivo translation of OraSE–K629M in E. coli, in vitro refolding of the enzyme employs a different folding mechanism. In both cases, the association of the S and E subunit is important for d‐ornithine aminomutase to maintain an active conformation.
Antisense glutaminase inhibition decreases glutathione antioxidant capacity and increases apoptosis in Ehrlich ascitic tumour cells
Authors: Lora Jorge , Alonso Francisco J. , Segura Juan A. , Lobo Carolina , Márquez Javier , Matés José M.
Published: October 2004

Glutamine is an essential amino acid in cancer cells and is required for the growth of many other cell types. Glutaminase activity is positively correlated with malignancy in tumours and with growth rate in normal cells. In the present work, Ehrlich ascites tumour cells, and their derivative, 0.28AS‐2 cells, expressing antisense glutaminase mRNA, were assayed for apoptosis induced by methotrexate and hydrogen peroxide. It is shown that Ehrlich ascites tumour cells, expressing antisense mRNA for glutaminase, contain lower levels of glutathione than normal ascites cells. In addition, 0.28AS‐2 cells contain a higher number of apoptotic cells and are more sensitive to both methotrexate and hydrogen peroxide toxicity than normal cells. Taken together, these results provide insights into the role of glutaminase in apoptosis by demonstrating that the expression of antisense mRNA for glutaminase alters apoptosis and glutathione antioxidant capacity.
Cardiovascular responses during bed‐to‐wheelchair transfers in frail elderly who live at home*
Authors: Hagiwara Akiko , Kanagawa Katsuko
Published: October 2004

Background:  The objective of this study is to determine the changes in cardiovascular responses during bed‐to‐wheelchair transfers in frail elderly people living at home and to determine the differences associated with different methods of transfer.

Methods:  Cardiovascular responses during such transfers were measured in 22 frail elderly subjects (mean age, 79.7 years) and 11 healthy elderly subjects (mean age, 79.8 years) living at home. The frail elderly subjects consisted of: 11 subjects who required additional help during the transfer; and 11 subjects who could perform the transfer either with some help or independently.

Results:  In the healthy subjects, diastolic blood pressure increased significantly 15 min after the transfer compared with the pretransfer measurement (P < 0.05). In the dependent group, there was no significant change in blood pressure after the transfer in three subjects. Only four subjects exhibited normal heart rate variability after the transfer. In the partially dependent or independent group, there was a significant increase in blood pressure just after the transfer (P < 0.05). The change in mean blood pressure in the dependent group was significantly lower than that of the partially dependent or independent group from just before the transfer to 15 min after the transfer (P < 0.05).

Conclusion:  These results suggest poor cardiovascular responsiveness in the ‘dependent’ subjects. In partially dependent or independent patients, independent transfers might result in cardiac overload. Blood pressure responses during bed‐to‐wheelchair transfers in frail elderly subjects living at home might differ according to the method of transfer.
Chronic Pain, Stress, and the Dynamics of Affective Differentiation
Authors: Davis Mary C. , Zautra Alex J. , Smith Bruce W.
Published: October 2004

AbstractWe describe a program of research examining how the relationship between positive and negative affect varies both between individuals and within individuals over time. This Dynamic Model of Affect (DMA) proposes that under conditions that promote maximal information processing, positive and negative affective systems function relatively independently. In contrast, under conditions characterized by uncertainty, including pain and stress, the affects become strongly inversely related. Included in our consideration are potential individual differences in the ability to sustain affective differentiation during pain and other stressors and the implications of this model for perceptions of social relations and for interventions to improve well‐being among the chronically ill.
When the Social Self Is Threatened: Shame, Physiology, and Health
Authors: Dickerson Sally S. , Gruenewald Tara L. , Kemeny Margaret E.
Published: October 2004

Abstract
Our program of research focuses on shame as a key emotional response to “social self” threats (i.e., social evaluation or rejection). We propose that shame may orchestrate specific patterns of psychobiological changes under these conditions. A series of studies demonstrates that acute threats to the social self increase proinflammatory cytokine activity and cortisol and that these changes occur in concert with shame. Chronic social self threats and persistent experience of shame‐related cognitive and affective states predict disease‐relevant immunological and health outcomes in HIV. Across our laboratory and longitudinal studies, general or composite affective states (e.g., distress) are unrelated to these physiological and health outcomes. These findings support a stressor‐ and emotional response‐specificity model for psychobiological and health research.
The Implicit Life Satisfaction Measure
Authors: Kim Do‐Yeong
Published: October 2004

The Implicit Association Test, developed by Greenwald and colleagues in 1998, was adapted to measure satisfaction with life by assessing the strength of automatic associations of My life with Good‐ versus Bad‐related words. A series of studies explored some psychometric as well as methodological properties of the Implicit Life Satisfaction measure (ILS). The ILS demonstrated good internal consistency and moderate temporal stability. Studies revealed that: (i) the type of stimuli used for target and attribute categories influences the magnitude of the ILS effect; (ii) participants could voluntarily suppress their satisfaction with life on the ILS, but not enhance it; and (iii) handedness of categories did not affect the participants’ performance on the ILS. Overall, the ILS measures are: (i) independent of traditional life satisfaction self‐report measures; and (ii) positive for most people.
Organizational identification and organizational commitment: Distinct aspects of two related concepts
Authors: Gautam Thaneswor , Van Dick Rolf , Wagner Ulrich
Published: October 2004

The conceptual differences between organizational commitment and identification are discussed theoretically and examined empirically. The present study is based on data of 450 employees of five different organizations in Nepal. A revised eight‐item scale was designed out of Cheney’s Organizational Identification Questionnaire to assess the core aspects of organizational identification. In confirmatory factor analyses, identification was found to be distinguishable from four related commitment concepts (i.e. affective, continuance, normative, and attitudinal commitment).
Lifelong learning and second‐order learning objects
Authors: Allert Heidrun , Richter Christoph , Nejdl Wolfgang
Published: October 2004

Current cultural, social, and economic trends challenge traditional concepts of learning and lifelong learning. This paper draws on the twofold nature of learning in a knowledge society and explores options for technological support. The concept of Second‐Order Learning Objects is introduced as a potential means to foster generative learning. Generative learning goes beyond that what is already known and extends or transforms the socially shared knowledge including its artefacts and practices. According to the notion of individual and social learning as a process of reflective action, the role of strategies and media for reflection and inquiry is stressed. This paper outlines the use of schematically represented strategies for learning and reflection and sketches important features of a pursuant modelling approach.
E‐portfolios: an assessment tool for online courses
Authors: Mason Robin , Pegler Chris , Weller Martin
Published: October 2004

This article considers the various uses of e‐portfolios in an educational context and looks at the particular characteristics of the electronic version of portfolios. It then focuses on the application of the e‐portfolio as an assessment method. A case is made for the use of the e‐portfolio as an appropriate end of course assessment process where learning objects are the basis of the course design. Evaluation data from such a course is presented. This is a post‐graduate online course run by the Institute of Educational Technology at the Open University. Conclusions are drawn from the evaluation about the appropriateness of e‐portfolios as an end of course assessment method.
Systemic absorptive capacity: creating early‐to‐market returns through R&D alliances
Authors: Newey Lance R. , Shulman Arthur D.
Published: October 2004

For most complex emergent technologies, product‐market success depends on efficient linkages between changing lead innovators within the R&D process. In this paper, our unit of analysis is a complex high technology product and the system of alliance linkages formed to progress a product through R&D milestones. We present a model and evidence for advancing our understanding of how achieving early‐to‐market returns depends on systemic absorptive capacity. This systemic absorptive capacity is the cumulative efficiency in the use of absorptive capacity to link changing lead innovators across successive milestones in R&D product development. We advance propositions of how systemic absorptive capacity can explain performance differences between rival product development systems competing for early‐to‐market returns with similar products through accelerating speed to market, cost and quality advantages. These explanations are contrasted with the conclusions of previous studies that have focused on absorptive capacity of single firms or single alliances in R&D.
Leveraging knowledge assets: combinative capabilities – theory and practice
Authors: Koruna Stefan
Published: October 2004

Since the publication of Prahalad and Hamel's (1990) seminal paper on core competencies, leveraging technological competencies has become a topic in the resource‐based literature. This paper focuses on the creation of combinative capabilities and explains the logic of leveraging resources by combining them. Furthermore, the paper explains on which company levels combinations can be expected to occur and how firms can apply combinations to commercial ends. A case study illustrates one possible way for firms to support such combinations and describes how companies can develop a new organisational form for R&D that is more able to overcome the limitations of functional and divisional forms of R&D.
The Lead User method: an outline of empirical findings and issues for future research
Authors: Lüthje Christian , Herstatt Cornelius
Published: October 2004

In order to reduce the risks of failure usually associated with NPD, leading companies such as 3M, HILTI, or Johnson&Johnson are increasingly working with so‐called Lead Users. Their identification and involvement is supported by the Lead User method – a multi stage approach aiming to generate innovative new product concepts and to enhance the effectiveness of cross‐functional innovation teams. While the Lead User method is frequently cited in the literature, yet, there are only limited attempts to comprehensively discuss how this approach is embedded in theories and empirical findings of innovation and marketing research. Therefore the Lead User method is in the focus of the present paper, both with respect to its theoretical foundation and its implementation into the innovation management system. First, empirical research on user innovations is reviewed to clarify the theoretical foundation of the Lead User method. Second the attention is drawn to the Lead User practice by discussing the various process steps of this specific approach on the basis of two applications of the method. Based on this discussion, we outline open questions related with the practical implementation of the Lead User method in order to start an agenda for future research.
Towards networked R&D management: the R&D approach of Sonera Corporation as an example
Authors: Blomqvist Kirsimarja , Hara Veikko , Koivuniemi Jouni , Äijö Toivo
Published: October 2004

In this paper the authors delineate the challenges of a dynamic environment to R&D management. The authors build on most recent ideas, such as the dynamic capability view of the firm, as strategic foundation for modern R&D management. Collaboration is emphasized as a meta‐capability for innovation. These ideas are merged into a ‘Networked R&D Management’ approach that emphasizes internal and external collaboration networks as critical for companies operating in a dynamic business environment. The approach is illustrated with ICT industry as an example. The implementation of Networked R&D Management is reflected in the illustrative case discussion of R&D management of Sonera Corporation.
Sectoral Selection and Informality: a Nicaraguan Case Study
Authors: Pisani Michael J. , Pagán José A.
Published: October 2004

Using microdata from the 1998 and 1993 Nicaraguan Living Standards Measurement Survey, this paper analyzes the relative size and attractiveness of formal and informal sector employment. Switching regression models of the formal/informal sector employment choice indicate that education across years and gender are the primary determinants of formal sector participation. Furthermore, the formal sector is characterized by positive selection. The results for the informal sector are less definitive, but are also suggestive of positive selection. These findings imply that the informal and formal sectors in Nicaragua contribute positively to the overall economy by attracting those individuals best suited for (in)formal sector employment.
Strategic Complementarity in Direct Investments
Authors: Matsumura Toshihiro
Published: October 2004

The paper investigates a three‐country duopoly model. Two developed countries have large markets and one developing country has a cost advantage. The author finds that strategic complementarity in location choice yields multiple equilibria. One is a cost‐oriented agglomeration of firms in the developing country and the other is a market‐oriented equilibrium where each firm locates in its developed home country. Also, private incentives for the cost‐oriented location are excessive (resp. insufficient) from the viewpoint of world welfare if firms choose their locations non‐cooperatively (resp. cooperatively).
Macroeconomic Effects of Capital Account Liberalization: the Case of Korea
Authors: Kim Soyoung , Kim Sunghyun Henry , Wang Yunjong
Published: October 2004

The macroeconomic effects of capital account liberalization in Korea are examined. Simple data analysis suggests that capital account liberalization substantially changed the nature and composition of capital flows. Based on the VAR model, the authors find the following stylized facts. First, after capital market liberalization, capital flows become less driven by current account imbalances and therefore become more autonomous. Second, capital account liberalization significantly changes the effects of capital flows on macroeconomic variables. Third, capital account liberalization is highly related to consumption and investment booms, and subsequent appreciation of nominal and real exchange rates, which leads to the current account worsening. Finally, there is strong evidence of sterilized foreign exchange market intervention in response to capital inflows.