bluuebunny/crossref_metadata_2025 huggingface dataset:
The art of financial relations: reflections on strategic growth
Authors: Hägg Claes , Preiholt Håkan
Published: February 2004

The purpose of the present article is to discuss the role of financial marketing in the creation of self‐reinforcing trends and bubbles. If the fundamental problems of financial marketing are not controlled, they can lead us to the world of the cynics, of raiders, of hostile takeovers where there is no free interplay of supply and demand. On the other hand, it would be wrong to consider every rise in the share price, which is not related to assets in place, as a bubble. The real art of financial marketing is to present to the public in an intelligible and convincing manner, the real options embedded in the firm's growth opportunities.
A learning perspective on caring: a view from the ground up
Authors: Bowerman Jennifer K.
Published: February 2004

In an interview, an adult learner with the Canadian School of Management discusses her research proposal aimed at strengthening the capability of the facility where she works to deal with clients suffering from Alzheimer’s disease (AD) and other forms of dementia. The learner describes her motivation for this kind of work. She describes how she will apply some of the action learning principles recently learned to bring a mix of people together to discuss and work through issues relating to the care of clients residing in the Alzheimer unit. Canadian statistics suggest that at this time, one in three adults over the age of 85 and 1 in 13 over the age of 65 is affected with Alzheimer’s or other forms of dementia. These numbers are expected to grow significantly as the population ages. The learner explains how, through her initiative, the facility will be more equipped to both meet the needs of current clients and those in the future.
The impact of an outpatient heart failure clinic on hospital costs and admissions
Authors: Gregoroff Susan J. , McKelvie Robert S. , Szabo Sylvia
Published: February 2004

This study of 216 congestive heart failure (CHF) patients at a large teaching hospital in south‐central Ontario was undertaken to determine whether the patients managed in an outpatient heart failure clinic used fewer hospital resources (as expressed in number of admissions, complexity of admission, and length of stay (LOS)) than a matched cohort who were not managed in an outpatient clinic. Statistical significance of LOS opportunities could not be demonstrated (owing to sample size), however, the heart failure clinic is making a positive impact on all types of admissions (CHF and non‐CHF) in terms of LOS and suggests that management in an outpatient setting for chronic disease states is important for acute care hospitals to consider.
Directed evolution relieves product inhibition and confers in vivo function to a rationally designed tyrosine aminotransferase
Authors: Rothman Steven C. , Voorhies Mark , Kirsch Jack F.
Published: February 2004

The Escherichia coli aspartate (AATase) and tyrosine (TATase) aminotransferases share 43% sequence identity and 72% similarity, but AATase has only 0.08% and 0.01% of the TATase activities (kcat/Km) for tyrosine and phenylalanine, respectively. Approximately 5% of TATase activity was introduced into the AATase framework earlier both by rational design (six mutations, termed HEX) and by directed evolution (9–17 mutations). The enzymes realized from the latter procedure complement tyrosine auxotrophy in TATase deficient E. coli. HEX complements even more poorly than does wild‐type AATase, even though the (kcat/Km) value for tyrosine exhibited by HEX is similar to those of the enzymes found from directed evolution. HEX, however, is characterized by very low values of Km and KD for dicarboxylic ligands, and by a particularly slow release for oxaloacetate, the product of the reaction with aspartate and a TCA cycle intermediate. These observations suggest that HEX exists largely as an enzyme–product complex in vivo. HEX was therefore subjected to a single round of directed evolution with selection for complementation of tyrosine auxotrophy. A variant with a single amino acid substitution, A293D, exhibited substantially improved TATase function in vivo. The A293D mutation alleviates the tight binding to dicarboxylic ligands as Kms for aspartate and α‐ketoglutarate are >20‐fold higher in the HEX + A293D construct compared to HEX. This mutation also increased kcat/KmTyr threefold. A second mutation, I73V, elicited smaller but similar effects. Both residues are in close proximity to Arg292 and the mutations may function to modulate the arginine switch mechanism responsible for dual substrate recognition in TATases and HEX.
Enterococcus faecalis mevalonate kinase
Authors: Hedl Matija , Rodwell Victor W.
Published: February 2004

Gram‐positive pathogens synthesize isopentenyl diphosphate, the five‐carbon precursor of isoprenoids, via the mevalonate pathway. The enzymes of this pathway are essential for the survival of these organisms, and thus may represent possible targets for drug design. To extend our investigation of the mevalonate pathway in Enterococcus faecalis, we PCR‐amplified and cloned into pET‐28b the mvaK1 gene thought to encode mevalonate kinase, the fourth enzyme of the pathway. Following transformation of the construct EFK1‐pET28b into Escherichia coli BL21(DE3) cells, the expressed C‐terminally hexahistidine‐tagged protein was purified on a nickel affinity support to apparent homogeneity. The purified protein catalyzed the divalent ion‐dependent phosphorylation of mevalonate to mevalonate 5‐phosphate. The specific activity of the purified kinase was 24 μmole/min/mg protein. Based on sedimentation velocity data, E. faecalis mevalonate kinase exists in solution primarily as a monomer with a mass of 32.2 kD. Optimal activity occurred at pH 10 and at 37°C. ΔHa was 22 kcal/mole. Kinetic analysis suggested that the reaction proceeds via a sequential mechanism. Km values were 0.33 mM (mevalonate), 1.1 mM (ATP), and 3.3 mM (Mg2+). Unlike mammalian mevalonate kinases, E. faecalis mevalonate kinase utilized all tested nucleoside triphosphates as phosphoryl donors. ADP, but not AMP, inhibited the reaction with a Ki of 2.7 mM.
Correlation between sequence hydrophobicity and surface‐exposure pattern of database proteins
Authors: Moelbert Susanne , Emberly Eldon , Tang Chao
Published: February 2004

Hydrophobicity is thought to be one of the primary forces driving the folding of proteins. On average, hydrophobic residues occur preferentially in the core, whereas polar residues tend to occur at the surface of a folded protein. By analyzing the known protein structures, we quantify the degree to which the hydrophobicity sequence of a protein correlates with its pattern of surface exposure. We have assessed the statistical significance of this correlation for several hydrophobicity scales in the literature, and find that the computed correlations are significant but far from optimal. We show that this less than optimal correlation arises primarily from the large degree of mutations that naturally occurring proteins can tolerate. Lesser effects are due in part to forces other than hydrophobicity, and we quantify this by analyzing the surface‐exposure distributions of all amino acids. Lastly, we show that our database findings are consistent with those found from an off‐lattice hydrophobic–polar model of protein folding.
Combination of multiple alignment analysis and surface mapping paves a way for a detailed pathway reconstruction—The case of VHL (von Hippel‐Lindau) protein and angiogenesis regulatory pathway
Authors: Sikora Sergey , Godzik Adam
Published: February 2004

Using the tumor suppressor VHL protein as an example, we show that detailed analysis of conservation versus variation pattern in the multiple alignment can be coupled with the genomic pathway/complex conservation analysis to provide a more complete picture of the entire interaction/regulatory network. Results from the present study have allowed us to hypothesize that two additional proteins are involved in the VHL‐mediated regulation of angiogenesis. Detailed modeling also has led to a prediction of the possible interaction mode between the known and the proposed parts of the VHL complex. To aid in an analysis of the VHL protein regulation of HIF‐1α degradation, an important and only partially understood process that directly influences angiogenesis, we performed a comprehensive search for the orthologs of the VHL as well as for VHL‐interacting proteins in all the available eukaryotic genomes. Analysis of a multiple alignment of thus identified VHL orthologs reveals an unusually high degree of conservation of the surface amino acid residues that almost exactly correspond to positions mutated in the VHL disease‐associated tumors. In addition, these positions form well‐defined clusters in three‐dimensional space, and presence or absence of individual clusters correlates with the presence or absence of pathway elements in different genomes. We have also shown that relation trees derived from the multiple sequence alignment, functional surface‐mapping, and HIF‐1α degradation pathway structure are in complete agreement, linking the functional and structural evolution of the VHL protein and VHL‐dependent HIF‐1α degradation complex.
The solution structure of the pH‐induced monomer of dynein light‐chain LC8 from Drosophila
Authors: Makokha Moses , Huang Yuanpeng Janet , Montelione Gaetano , Edison Arthur S. , Barbar Elisar
Published: February 2004

The structure of Drosophila LC8 pH‐induced monomer has been determined by NMR spectroscopy using the program AutoStructure. The structure at pH 3 and 30°C is similar to the individual subunits of mammalian LC8 dimer with the exception that a β strand, which crosses between monomers to form an intersubunit β‐sheet in the dimer, is a flexible loop with turnlike conformations in the monomer. Increased flexibility in the interface region relative to the rest of the protein is confirmed by dynamic measurements based on 15N relaxation. Comparison of the monomer and dimer structures indicates that LC8 is not a domain swapped dimer.
Evidence of perturbations induced by reproduction on somatic growth and microincrement deposition in Oreochromis niloticus otoliths
Authors: Massou A. M. , Panfili J. , Le Bail P.‐Y. , Laë R. , Mikolasek O. , Fontenelle G. , Baroiller J. F.
Published: February 2004

The direct effects of reproduction (energy expenditure for gametogenesis) were studied in gonadectomized Oreochromis niloticus females, incapable of reproducing. The indirect effects of reproduction were studied in intact females that had either mouth brooded their eggs or not. In gonadectomized females the slowing of growth observed in the marginal zone of their otoliths coincided with the time of gonad regeneration. The responses were very varied in the group of intact females. In these females, there was less otolith growth and more checks were observed on the otoliths. The results showed that reproduction influenced the growth of fish and their otoliths leading to a significant underestimate of the number of primary increments during this period of life.
Influence of egg vitamin A status and egg incubation temperature on subsequent development of the early vertebral column in Atlantic salmon fry
Authors: Ørnsrud R. , Wargelius A. , Sæle Ø. , Pittman K. , Waagbø R.
Published: February 2004

The effect of egg vitamin A (VA) status and egg incubation temperature on the development of spinal disorders was investigated in Atlantic salmon Salmo salar fry. Atlantic salmon eggs were sorted into two groups with high VA (3·3 ± 0·1 μg retinol g−1 dry mass) and low VA (2·2 ± 0·3 μg retinol g−1 dry mass) status before fertilization and incubated at high (14° C) or low (8° C) temperature from 133 day degrees until the onset of feeding. High egg incubation temperatures increased the concentration of retinol in the eggs: the high VA and high temperature group displayed a significantly higher retinol concentration than the high VA and low temperature group (P = 0·001). After hatching, all experimental groups increased their retinol concentration. The source of the increased retinol levels was probably retinal, although astaxanthin may also be a VA precursor after hatching. Atlantic salmon fry incubated at high temperatures had increased amounts of notochord tissue. When measuring morphogenic activity in the notochord using the expression of sonic hedgehog (shh, mRNA), however, no significant difference was found between the experimental groups. No clear effect of VA status or incubation temperature could be found on the formation of the early vertebral column although Atlantic salmon fry incubated at low temperatures had less regular constrictions of the prospective vertebral column than fry incubated at high temperatures.
Endocrine disruption in juvenile roach from English rivers: a preliminary study
Authors: Beresford N. , Jobling S. , Williams R. , Sumpter J. P.
Published: February 2004

Juvenile roach Rutilus rutilus from seven rivers of varying water quality were examined for evidence of endocrine disruption. The majority of roach from five of these rivers had female‐like reproductive ducts. The results suggest that juvenile, rather than adult, fish could be used in studies of endocrine disruption in wild fish populations.
Variations of sperm release in three batches of zebrafish
Authors: Kemadjou Njiwa J. R. , Müller P. , Klein R.
Published: February 2004

By collecting and counting the number of sperm released during separate matings in three batches of zebrafish Danio rerio, aged 3–4, 4–5 and 5–6 months, males were observed to release sperm before the female started laying their eggs. After the female left the nest, the number and motility of sperm and life span of sperm of younger fish were higher than those of older fish in water samples collected under the nest and at the surface of the tank. Sperm were released in the form of sperm trails laid on the nest surface, subsequently active spermatozoa left the trails and moved in the water for several minutes. Sperm trails consisted of bands of viscous material in which the sperm were embedded. In most cases eggs were not laid directly over the sperm trail, suggesting that sperm may contact the eggs after the latter are released into the water. In all the three tested groups there was no significant difference (P > 0·05) between the number of sperm collected on some portions of the acetate sheets which lined the nest ceiling. This result demonstrated that the greater activity of younger fish accelerated the sperm dispersal in water. Male sperm duct glands, seminal vesicles, known to secrete mucosubstances are probably involved in the production of sperm trails. The possible influence of insemination on the mating style of zebrafish is discussed.
Fish assemblage changes relative to environmental factors and time in the Warta River, Poland, and its oxbow lakes
Authors: Penczak T. , Galicka W. , Głowacki Ł. , Koszaliński H. , Kruk A. , Zięba G. , Kostrzewa J. , Marszał L.
Published: February 2004

Four oxbow lakes and two neighbouring sections of their parent Warta River (Odra River system, Poland) were sampled to investigate differences in fish assemblages between habitats in 1999–2000. Additional comparisons were made with 12 other oxbow lakes in this section of the river that were sampled 30–40 years ago. Downstream of a man‐made reservoir, higher species number, diversity and evenness were recorded in oxbow lakes than in the river channel. Upstream of the reservoir, differences in these variables from both habitats were insignificant. Fluvial and stagnant water samples were clearly separated in the multivariate space of a detrended correspondence analysis (DCA). For two oxbow lakes and two neighbouring sections of the Warta River, 12 abiotic and biotic environmental variables were available, and only velocity, water temperature and conductivity were significantly correlated with canonical correspondence analysis (CCA) axes. Fish assemblages of four recently investigated oxbow lakes were clearly separated in the multivariate space of DCA from other neighbouring oxbows sampled 30–40 years ago. Species previously subdominant were becoming rare. Oxbow lakes that are continuously or at least periodically connected with the channel are indispensable for maintaining high biodiversity and a sustainable fishery in the river system.
Factors influencing the spawning migration of female anadromous brown trout
Authors: Svendsen J. C. , Koed A. , Aarestrup K.
Published: February 2004

Radio telemetry was employed to study movements of adult female anadromous brown troutSalmo trutta(sea trout) during upstream spawning migration and following spawning in a stream with tributaries. Sea trout were monitored by manual tracking and by automatic listening stations. The latter suggested that initiation of upstream migration was positively correlated with stream discharge. Individual sea trout performed repeated upstream migration ‘initiations’(visits) to areas where they were detected by the automatic listening stations. The first and subsequent upstream migration ‘initiations’ occurred under conditions of similar water temperature and stream discharge. Manual tracking indicated that in the pre‐spawning state, the distance migrated over 3 days was positively correlated with stream discharge and water temperature, whereas in the post‐spawning state, the total distance migrated was not correlated with any of these two environmental variables.
Seasonal bottlenecks in diet shifts and growth of smelt in a large eutrophic lake
Authors: Vinni M. , Lappalainen J. , Malinen T. , Peltonen H.
Published: February 2004

Seasonal growth of smelt Osmerus eperlanus was studied in the Kiihkelyksenselkä basin in the eutrophic Lake Hiidenvesi, southern Finland. The growth of age 1+ and 2+ year smelts was very low probably due to the discontinuous supply of large invertebrates Chaoborus flavicans and Mysis relicta. Diet shift back to zooplankton in autumn, suggested the existence of a bottleneck in the growth of these age groups. Slow growth rate was further intensified by the onset of maturity at age 2 years, combined with the high diet and habitat overlaps between similar‐sized 1+ and 2+ year smelts. Older 3+ and 4+ year smelts shifted to piscivory, i.e. cannibalism, during the growing season, which was seen as rapid increases in their growth rates.
The Role of Serum Immunoglobulin E in the Pathogenesis of Plasmodium falciparum Malaria in Ivorian Children
Authors: Seka‐Seka J. , Brouh Y. , Yapo‐Crézoit A. C. , Atseye N. H.
Published: February 2004

The aim of the study was to determine the role of immunoglobulin E (IgE) in the pathogenesis of Plasmodium falciparum malaria in Ivorian children. The study comprised of 90 Ivorian children of both sexes, aged 6–72 months: 30 children suffering from severe malaria, 30 suffering from mild malaria and 30 in good heath (serving as the control population). The children underwent a total serum IgE test for the determination of haemoglobin and platelet level and parasite density. We noted a significant rise in IgE level in the children affected with malaria. The level was higher when the malaria was more severe, increasing from 84.61 kUI/l in the control children to 339.9 kUI/l in the children with mild malaria and 659.9 kUI/l in children with severe malaria. Among the comatose patients with severe malaria, the increase in IgE level was related to the level of deterioration of the consciousness. Moreover, we noted a negative correlation between IgE level and the level of haemoglobin and between the IgE level and platelet level. These results are in accordance with the results found in literature and confirm the use of IgE level as an indicator of P. falciparum malaria.
Generation of Amyloid A Protein by the Cell Lines from Amyloid‐Susceptible and ‐Resistant Mice
Authors: Ham D. , Skoryna S. C.
Published: February 2004

It has been proposed that impaired degradation is the cause of amyloid A (AA) formation in reactive amyloidosis (Ham et al., Scand J Immunol 1997; 45: 354–60). The current SDS‐PAGE of the culture medium showed that the macrophage cell line from the amyloid‐susceptible mouse strain (ANA1) degraded amyloid precursor protein serum amyloid A into the AA‐like amyloidogenic product of approximately 8.6 kDa but went no further, whereas cells from the resistant strain (A/J10) cleared the AA‐like derivates proceeding to approximately 7.7 kDa products within the incubation period. Degradation occurred in the chemically defined medium at a slower rate than in the medium with serum. This may imply that a lack of the serum components as well as impaired degradation could contribute to the development of amyloidosis.
Modification of the Inhibitory Amino Acid for Epitope Peptide Binding onto Major Histocompatibility Complex Class II Molecules Enhances Immunogenicity of the Antigen
Authors: Chang S.‐H. , Kim J. , Lee K.‐Y. , Kim H.‐J. , Chung Y. J. , Park C. U. , Kim B. S. , Jang Y.‐S.
Published: February 2004

Previously, the arginine at hen egg‐white lysozyme 61 (HEL 61) was characterized as inhibiting T‐lymphocyte stimulation due to the inefficient binding of the arginine‐containing epitope peptide to the corresponding major histocompatibility complex class II molecules in C57BL/6 mice. In this study, we produced recombinant HEL, with arginine or alanine at HEL 61, and compared its ability to induce immune responses in mice to see whether modification of an inhibitory amino acid could enhance the immunogenicity of an inefficient antigen. Immunization of the mice with modified HEL induced strong antibody and T‐cell immune responses against the native antigen. The enhanced T‐cell immune response was due to a more specific elevation of the T‐cell responses to the HEL 46–61 epitope region than to other epitope regions, although recognition of the other epitope peptides of HEL was generally increased. Mass spectrometric analyses of the epitope peptides generated by splenic antigen‐presenting cells indicated that production of the epitope peptides encompassing HEL 46–61 was efficient using the modified antigen. These results suggest that modification of the critical amino acid residue(s) involved in hampering induction of an efficient immune response is an effective method to improve the immunogenicity of an inefficient antigen.
Humoral Proinflammatory Cytokine and SAA Generation Profiles and Spatio‐Temporal Relationship Between SAA and Lysosomal Cathepsin B and D in Murine Splenic Monocytoid Cells During AA Amyloidosis
Authors: Phipps‐Yonas H. , Pinard G. , Ali‐Khan Z.
Published: February 2004

Evidence shows that tissue macrophages (MΦs), in mice undergoing AA amyloidosis, endocytose acute‐phase humoral serum amyloid A (SAA) and traffic it to lysosomes where it is degraded. Incomplete degradation of SAA leads to intracellular nascent AA fibril formation. In vitro, cathepsin (Cat) B is known to generate amyloidogenic SAA derivatives, whereas Cat D generates non‐amyloidogenic SAA derivatives, and interferon (IFN‐γ)‐treated MΦs show selective increase in Cat B concentration, a factor conducive to AA amyloidogenesis. To understand the cumulative effect of these factors in AA amyloidosis, humoral levels of SAA, IFN‐γ, tumour necrosis factor (TNF‐α) and granulocyte–macrophage colony‐stimulating factor were determined in azocasein (AZC)‐treated CD‐1 mice. We correlated these responses with the spatio‐temporal distribution of SAA, Cat B‐ and Cat D‐immunoreactive splenic reticuloendothelial (RE) cells. AZC‐treated CD‐1 mice similar to that of A/J mice showed partial amyloid resistance; their peak humoral IFN‐γ and SAA responses overlapped during the pre‐amyloid phase. Unexpectedly, Cat D immunoreactivity (IR), instead of Cat B IR, was predominant in the splenic RE cells, indicating an apparent lack of causal relationship between IFN‐γ‐mediated increase in Cat B expression. Partial amyloid resistance in CD‐1 mice, probably a genetic trait, may be linked to high levels of Cat D expression, causing a delay in nascent AA fibril formation.
Clustering of C‐Type Lectin Natural Killer Receptor‐Like Loci in the Bony Fish Oreochromis niloticus
Authors: Kikuno R. , Sato A. , Mayer W. E. , Shintani S. , Aoki T. , Klein J.
Published: February 2004

The genome of the cichlid (teleost) fish Oreochromis niloticus contains a set of genes which encode group V C‐type lectin proteins homologous to the mammalian NKG2/CD94 family of natural killer (NK) cell receptors. To determine the genomic organization of these killer cell‐like receptor (KLR) genes, an O. niloticus BAC library was screened with a cDNA probe derived previously from an expressed sequence tag of the related cichlid species Paralabidochromis chilotes. Four distinct KLR‐bearing BAC clones were analysed, three of which could be assembled into a contig. One of the clones was sequenced in its entirety, whereas the others were partially sequenced to identify the KLR loci borne by them. Altogether, 28 distinct KLR loci were identified, of which at least 26 occupy a single chromosomal region, the KLR complex. One half of the loci appear to be occupied by pseudogenes. Compared to the human NK cell receptor complex, the Oreochromis KLR complex is more compact and, apart from transposons, appears to contain only KLR loci. The gene density of the complex is one KLR locus per 18 kb of sequence. All the KLR loci constituting the complex are derived from a single most recent common ancestor, which is estimated to have existed 7.7 million years ago. The 180 kb of the determined sequence is a mosaic of blocks of similar segments reflecting a complex history of duplications, deletions and rearrangements. The transposons found in the sequenced part belong to the TC1, Xena, CR1 and TX1 families.
Proteasomal Targeting and Minigene Repetition Improve Cell‐Surface Presentation of a Transfected, Modified Melanoma Tumour Antigen
Authors: Rasmussen A. B. , Zocca M.‐B. , Bonefeld C. M. , Von Essen M. , Lauritsen J. P. H. , Tomra S. , Ødum N. , Geisler C.
Published: February 2004

Melanoma antigen recognized by T cell 1 (MART‐1) is regarded as a candidate peptide for vaccination against malignant melanoma, and it is of importance to develop strategies to improve the vaccine‐elicited T‐cell activation towards MART‐1. T‐cell activation is, among other determinants, dependent on the density of specific major histocompatibility complex–peptide complexes on the surface of the antigen‐presenting cell. In this study, we explored the cell‐surface presentation of a substituted MART‐1 peptide encoded by transfected minigenes. We investigated the potential of proteasomal targeting compared to non‐proteasomal targeting of the epitope to increase its cell‐surface presentation. Furthermore, we explored the potential of incorporating multiple minigenes instead of one to increase cell‐surface presentation. We show that both proteasomal targeting and repetition of the minigene increase cell‐surface presentation of the epitope and propose both these approaches as potential strategies in DNA vaccines to increase MART‐1‐specific T‐cell activation.
Proliferative and Cytotoxic Response of Human Natural Killer Cells Exposed to Transporter Associated with Antigen‐Processing‐Deficient Cells
Authors: Cerboni C. , Öberg L. , Terrazzano G. , Zappacosta S. , Carbone E. , Kärre K.
Published: February 2004

In transporter associated with antigen‐processing (TAP)‐deficient patients affected by a severe downmodulation of human leucocyte antigen class I (HLA‐I) molecules, natural killer (NK) cells have an increased expression of the inhibitory receptor CD94/NKG2A. Focusing our attention on NK cells, we have investigated the phenotype, function and proliferative response of peripheral blood lymphocytes (PBLs) derived from healthy donors after coculturing with TAP (T2)‐ or HLA‐I‐deficient (721.221) cell lines and their related HLA‐I‐expressing transfectants (T3 and DT360, respectively). After 4 days, NK cells cocultured with T2 cells had a threefold increased CD94 expression compared to NK cells cocultured with T3. This increase was due to proliferation of the CD56brightCD94bright subset. In contrast, expression of other inhibitory receptors [killer cell immunoglobulin (Ig)‐like receptors] was variable during time and was not related to HLA‐I molecules expressed by stimulating cells. Similar results were obtained using HLA‐I‐deficient cells (721.221). The PBLs cocultured for 4 days with T2 cells displayed enhanced cytotoxic responses. The results suggest that CD56brightCD94bright NK cells are induced to proliferate and kill in response to a TAP‐deficient environment. The changes seen in the NK‐cell compartment were partially contributed by T lymphocytes present in the coculture. These data could explain the increased CD94 expression and autoimmune manifestations observed in TAP‐deficient patients.
Immunoglobulin Levels Amongst Persons with and without Human Immunodeficiency Virus Type 1 Infection in Uganda and Norway
Authors: Lugada E. S. , Mermin J. , Asjo B. , Kaharuza F. , Downing R. , Langeland N. , Ormaasen V. , Bruun J. , Awor A. C. , Ulvestad E.
Published: February 2004

CD4+‐cell count and viral load monitoring are expensive and unavailable to most human immunodeficiency virus (HIV)‐infected people in Africa. In an attempt to evaluate alternative methods for monitoring antiretroviral (ARV) therapy, we measured concentrations of immunoglobulin (Ig)A, IgM, IgG and IgG1 amongst adults with and without HIV in Uganda and Norway. We adjusted for disease severity by stratifying HIV‐positive subjects on CD4+‐cell counts above and below 200 cells/µl. Median serum levels of IgG, IgG1 and IgA were significantly higher in HIV‐positive persons compared with HIV‐negative persons in both countries (P < 0.001 and P = 0.018 for IgA in Ugandan patients). Levels of IgA in Ugandan HIV‐negative subjects were significantly lower than those in HIV‐positive subjects with low CD4+ compared with those with high CD4+‐cell counts (P < 0.001 and P = 0.069, respectively). IgM levels were different between the HIV‐negative and the two HIV‐positive groups in Norway (P < 0.001). The mean levels of IgM, IgG and IgG1 in HIV‐negative and ‐positive African subjects were generally higher than those in comparable groups of Western subjects. Our results verify that levels of IgA, IgG and IgG1 vary between HIV‐negative and ‐positive individuals in both study populations. Their determination may be useful in monitoring both disease progression and response to ARV therapy.
Indoleamine 2,3‐Dioxygenase is Necessary for Cytolytic Activity of Natural Killer Cells
Authors: Kai S. , Goto S. , Tahara K. , Sasaki A. , Tone S. , Kitano S.
Published: February 2004

Indoleamine 2,3‐dioxygenase (IDO) is a tryptophan catabolic enzyme that is widely distributed in various tissues. In peripheral blood mononuclear cells (PBMCs), production of IDO by macrophages or dendritic cells has been reported to inhibit T‐cell activation and proliferation. In the present study, we have determined that other phenotypes of PBMCs also express IDO. In cultures of PBMCs, IDO was found predominantly in monocyte by immunohistochemistry. Reverse transcriptase polymerase chain reaction analysis showed that IDO mRNA was expressed in T lymphocytes, B lymphocytes and natural killer (NK) cells and that expression was increased upon activation with interferon‐γ. The cytotoxicity of NK cells against K562 and HepG2 cells was reduced by IDO inhibitor. These results suggest that IDO in NK cells is essential for NK cells to generate killing activity against cancer cells.
In Vitro Study of the Long‐Term Effects of Post‐Traumatic Splenectomy on Cellular Immunity
Authors: Karakantza M. , Theodorou G. L. , Mouzaki A. , Theodori E. , Vagianos C. , Maniatis A.
Published: February 2004

The purpose of this study was to investigate the effect of splenectomy on cellular immunity. We studied the cellular phenotype and type 1 [interferon‐γ, interleukin‐2 (IL‐2)] and type 2 (IL‐4 and IL‐10) cytokine‐producing peripheral blood CD4+ and CD8+ T lymphocytes in 22 healthy adults who had undergone post‐traumatic splenectomy about 1 to 35 years ago. Splenectomy resulted in a long‐term reduction of the percentage of CD4+CD45RA+ cells and a late increase of the percentage and absolute numbers of T‐cell receptor γ/δ cells. Stimulation with Staphylococcal enterotoxin B resulted in normal IL‐2 production by CD4+ T cells, indicating that the naïve cells were not anergic. Splenectomy also resulted in long‐term priming of both CD4+ and CD8+ T cells. During the first 8 years, both type 1 and type 2 CD4+ T cells were primed to varying degrees. About 8 years later, the percentage of primed type 2 CD4+ T cells subsided, but that of type 1 CD4+ T cells, although decreased, remained detectable over a longer period. Priming of CD8+ T cells persisted throughout the study period. The long‐term priming of type 1 CD4+ and CD8+ T cells, which may result in partial impairment of T‐cell functions, may explain reported defects of immune responses to recall antigens in splenectomized individuals. In addition, changes in the profile of primed CD4+ T cells with time may be clinically relevant to relapses in autoimmune thrombocytopenia after splenectomy.
Immunodominant B‐Cell Epitope in the Mce1A Mammalian Cell Entry Protein of Mycobacterium tuberculosis Cross‐Reacting with Glutathione S‐Transferase
Authors: Harboe M. , Das A. K. , Mitra D. , Ulvund G. , Ahmad S. , Harkness R. E. , Das D. , Mustafa A. S. , Wiker H. G.
Published: February 2004

The TB1‐5 76C monoclonal antibody raised against a synthetic 60‐mer peptide in the N‐terminal part of the Mce1A mammalian cell entry protein of Mycobacterium tuberculosis has previously been shown to react with a linear epitope in the KRRITPKD region, residues 131–138 in Mce1A, and to cross‐react with Mce1F. Six additional monoclonal antibodies raised against the same peptide were also shown to cross‐react with Mce1F. Four of them reacted with a linear epitope in the same area, indicating that this area is immunodominant but showed distinct differrences in fine specificity. Two monoclonal antibodies did not react with synthetic peptides from this region on the solid phase in enzyme‐linked immunosorbent assay, indicating greater influence of conformation on reactivity. None of the monoclonal antibodies reacted with 14‐mer synthetic peptides from the corresponding area in Mce2A, Mce3A, Mce4A, M. avium, M. smegmatis or M. leprae. The reaction pattern of the monoclonal antibodies was analysed in relation to our model of the Mce1A molecule (AK Das et al. Biochem Biophys Res Commun 2003;302:442–7).The epitope is located on the surface of Mce1A, at the distal β‐strand‐loop region in the β‐domain supporting its potential role in promoting uptake of M. tuberculosis in host cells. Monoclonal antibody TB1‐5 19C cross‐reacted with glutathione S‐transferase of Schistosoma japonicum containing a PKE triplet. Monoclonal antibody TB1‐5 76C gave a major band at about 44 kDa in Western blotting of M. tuberculosis sonicate, whereas polyclonal rabbit anti‐Mce1A peptide antibodies reacting with the extended TTPKNPTKRRITPKDVI area of Mce1A showed a distinct band above the 160 kDa molecular mass standard.
Plaque development in relation to the periodontal condition and bacterial load of the saliva
Authors: Rowshani B. , Timmerman M. F. , Van der velden U.
Published: February 2004

Aim: To investigate the influence of the oral bacterial load on plaque development in various groups of periodontitis patients and in healthy subjects.

Material and Methods: This study included subjects with a healthy periodontium, a healthy reduced periodontium after treatment, an inflamed reduced periodontium after treatment and untreated periodontitis. At the start of the study, subjects were instructed to rinse with 10 ml reduced transport fluid (RTF) for 10 s in order to evaluate the oral bacterial load. The microbiological evaluation included anaerobe culture and phase‐contrast microscopy. Next, the amount of plaque and the clinical condition were evaluated. Thereafter, all supragingival plaque was removed and patients were instructed to refrain from all oral hygiene procedures for 19 h. Subsequently, the rinsing procedure and the evaluation of the amount of plaque were repeated.

Results: The amount of plaque that developed in 19 h was significantly higher in the untreated periodontitis group as compared with the two healthy groups. In case of an inflamed reduced periodontium, sites with deep pockets developed more plaque in 19 h than sites with shallow pockets. The number of bacteria present in the rinsing samples of the two inflamed groups was considerably higher than of the two periodontally healthy groups. A significant correlation was found between the bleeding index at intake and the plaque index at 19 h. No correlations were found between gingival recession and the bacterial counts at intake, and the plaque index at 19 h.

Conclusion: The present findings support the concept that the periodontal condition is the dominating factor in relation to the rate of plaque formation. The number of bacteria present in the oral cavity as ascertained by means of a rinsing sample does not seem to play a role.
Patient‐based assessments of clinical periodontal conditions in relation to alveolar bone loss
Authors: Renvert S. , Persson G. R.
Published: February 2004

Background: Limited subject‐based information exists on the relationship between clinical and radiographic periodontal data.

Aims: To use subject‐based data to assess the extent of concurrence between clinical and radiographic information, and to study what clinical information best predicts alveolar bone loss (ABL).

Material and Methods: Subject‐based data on smoking habits, bleeding on probing, plaque scores, pocket probing depth (PD), and evidence of alveolar BL were obtained, and functional periodontal pentagon risk diagrams (PPRDs) were studied from 168 consecutive subjects attending a medical clinic.

Results: The mean age of the subjects was 62.7 years (SD±9.0). The average number of teeth was 21.3 (SD±8.0) with on average 5.6 molars remaining (SD± 3.9). In this subject cohort, 33.1% had never smoked, 44.2% had quit smoking, and 22.7% were currently smokers. Mean plaque and bleeding scores were high or 60.2% (SD±24.0) and 53.1% (SD±23.6), respectively. PDs 6.0 mm were found in 55.9% of the subjects. Binary logistic regression analysis demonstrated that tooth loss and proportional plaque scores were the predominant factors included in the equations associated with ABL. Wald coefficients varied between 3.99 and 9.15, and with p‐values between 0.05 and 0.01. When included, the PPRD score became the exclusive factor at several cut‐off levels (Wald's coefficients between 19.8 and 15.6, p<0.001). Consequently, the best receiver operator curve was identified for the PPRD at the >40% cut‐off ABL level (area under the curve: 0.81; 95% CI: 0.74–0.89; p<0.001).

Conclusions: The number of teeth lost and the proportion of plaque scores provided significant predictive factors for ABL. The functional PPRD demonstrated an exclusive and highly predictable association with ABL. Subject‐based proportional data for PDs >4.0 mm provided poor substitute measures for the extent of ABL.
Influence of a SLS‐containing dentifrice on the anti‐plaque efficacy of a chlorhexidine mouthrinse
Authors: Van Strydonck D. A. C. , Scalé S. , Timmerman M. F. , Van der Velden U. , Van der Weijden G. A.
Published: February 2004

Background: Chlorhexidine (CHX) and sodium lauryl sulphate (SLS), the most widely used detergent in dentifrice, may counteract. Consequently, studies about this interaction suggested that care is required when combining both these compounds, even when they are introduced separately into the oral cavity. The purpose of the present study was to investigate the effect of toothbrushing with a SLS‐containing dentifrice in one jaw, on the plaque inhibition of a CHX mouthrinse in the opposite jaw during a 4‐day study period.

Methods: The study was an examiner‐blind, randomised two‐cell, crossover design.

It used a 4‐day plaque accumulation model to compare two different oral hygiene regimens with a washout period of 17 days. Sixteen healthy volunteers were enrolled in the study and received a thorough dental prophylaxis at the beginning of each 4‐day test period. One jaw (upper or lower) was randomly assigned as the “study” jaw. The opposite jaw was assigned as the “dentifrice” jaw and served only to introduce the effect of brushing with a dentifrice in the study model. Two oral hygiene regimens were evaluated. During one randomly assigned test period, the “dentifrice” jaw was treated by toothbrushing with a 1.5% SLS‐containing dentifrice and rinsed together with the “study” jaw with 0.2% CHX, thus forming regimen 1. As a control during the other test period, both the “dentifrice” jaw and “study” jaw were only rinsed with 0.2% CHX, forming regimen 2. No other oral hygiene methods were allowed. After 4 days of undisturbed plaque accumulation, the amount of plaque was evaluated (Silness & Löe 1964). The “study” jaw was used to study the effect of the two regimens on the level of plaque accumulation at the end of the 4‐day period.

Results: The overall plaque index was 0.36 for regimen 1 and 0.34 for regimen 2. There was no significant difference in plaque accumulation between the two regimens.

Conclusions: Within the limitations of the present study design, it can be concluded that ordinary brushing with a 1.5% SLS‐containing dentifrice (Colgate Bi‐Fluor), followed by rinsing with water does not appear to reduce the level of plaque inhibition offered by a post‐brushing CHX rinse.
Influence of the mineral content and morphological pattern of artificial root caries lesion on composite resin bond strength
Authors: Hara Anderson T. , Queiroz Celso S. , Giannini Marcelo , Cury Jaime A. , Serra Mônica C.
Published: February 2004

Dentine substrates with different mineral contents and morphological patterns were created by submitting root slabs to the following treatments: (A) immersion in artificial saliva during the experimental period (control), (B) demineralization for 32 h to induce caries lesion (demineralized group), and (C) demineralization for 32 h followed by remineralization for 8 d (remineralized group). The slabs were longitudinally sectioned, the mineral content was determined by cross‐sectional microhardness, and the bond strength of an adhesive system/composite resin was assessed using a microtensile bond strength test. The dentine morphology after the treatments as well as the failure pattern of the debonded specimens was examined by scanning electron microscopy. Statistically significant differences were found in mineral content. Morphological analysis showed marked differences between the patterns of demineralized and remineralized substrates. The bond strength mean value of the control A did not differ from the group B, but was statistically higher than the group C. Since no linear relationship was found between dentine mineral content and bond strength values, it could be suggested that the morphological pattern may be more relevant than the mineral content to explain the bond strength of composite resin to dentine.
Susceptibility of deciduous and permanent enamel to dietary acid‐induced erosion studied with atomic force microscopy nanoindentation
Authors: Lippert Frank , Parker David M. , Jandt Klaus D.
Published: February 2004

The initial stages of dental enamel demineralization by dietary acids are of particular clinical relevance. Some authors have reported a difference in the susceptibility of deciduous and permanent enamel to erosion, although other studies could not confirm these findings. The aim of the present study was therefore to investigate whether there are differences in the susceptibility of deciduous and permanent enamel to dietary acid induced erosion (demineralization). Nanoindentation combined with atomic force microscopy was used to investigate the erosive effect of four different drinks (cola, lemonade, juice drink, and water) on enamel at early stages in vitro. Surface nanohardness and reduced elastic modulus were obtained for the soft drink‐treated enamel samples as a function of the exposure time. The results obtained showed that the four drinks had widely differing erosive effects due to their diverse compositions. Water did not show statistically significant changes in nanomechanical properties for all exposure times compared with untreated enamel. Exposure of enamel to cola, lemonade and the juice drink led to a statistically significant surface softening of the enamel with cola and the lemonade having a much stronger softening effect than the juice drink. For longer exposure times enamel softening increased for cola and lemonade and stayed unchanged for the juice drink. Deciduous enamel was not found to be more susceptible to erosion than permanent enamel under the conditions of the present study.
NO‐cGMP signaling molecules in the rat epithelial rests of Malassez
Authors: Korkmaz Yüksel , Bloch Wilhelm , Behrends Sönke , Schröder Hannsjörg , Addicks Klaus , Baumann Michael A.
Published: February 2004

The epithelial rests of Malassez (ERM) are derived from the disintegrating epithelial root sheath of Hertwig that guides root formation during tooth development. Low concentrations of nitric oxide (NO) produced by NO‐synthase I (NOS I) and NOS III activate intracellular soluble guanylate cyclase (sGC) to produce intracellular cyclic guanosine 3′:5′‐monophosphate (cGMP), which triggers rapid cellular responses such as cell proliferation, cell differentiation, and apoptosis under physiological conditions. The presence of NOS I–III, sGC (α2‐ and β1‐subunits) and cGMP in the ERM was investigated by immunohistochemistry. Rat molars with periodontium were perfusion and postfixed, decalcified, frozen‐sectioned, and sections were immunostained. NOS I, NOS III, sGC (α2‐ and β1‐subunits) and cGMP were localized with different densities in the ERM. The presence of NOS II in the ERM varied. The localization of NOS I, NOS III, sGC and cGMP in the ERM indicates an involvement of NO and/or NO‐cGMP signal pathway molecules in homeostasis of a variety of physiological processes in the ERM. These could include regulation of cell proliferation, cell differentiation and apoptosis.
A wheat gene encoding an aluminum‐activated malate transporter
Authors: Sasaki Takayuki , Yamamoto Yoko , Ezaki Bunichi , Katsuhara Maki , Ahn Sung Ju , Ryan Peter R. , Delhaize Emmanuel , Matsumoto Hideaki
Published: February 2004

The major constraint to plant growth in acid soils is the presence of toxic aluminum (Al) cations, which inhibit root elongation. The enhanced Al tolerance exhibited by some cultivars of wheat is associated with the Al‐dependent efflux of malate from root apices. Malate forms a stable complex with Al that is harmless to plants and, therefore, this efflux of malate forms the basis of a hypothesis to explain Al tolerance in wheat. Here, we report on the cloning of a wheat gene, ALMT1 (aluminum‐activated malate transporter), that co‐segregates with Al tolerance in F2 and F3 populations derived from crosses between near‐isogenic wheat lines that differ in Al tolerance. The ALMT1 gene encodes a membrane protein, which is constitutively expressed in the root apices of the Al‐tolerant line at greater levels than in the near‐isogenic but Al‐sensitive line. Heterologous expression of ALMT1 in Xenopus oocytes, rice and cultured tobacco cells conferred an Al‐activated malate efflux. Additionally, ALMT1 increased the tolerance of tobacco cells to Al treatment. These findings demonstrate that ALMT1 encodes an Al‐activated malate transporter that is capable of conferring Al tolerance to plant cells.