bluuebunny/crossref_metadata_2025 huggingface dataset:
Mapping of genes that control the antibody response to human factor IX in mice
Authors: Lozier Jay N. , Tayebi Nahid , Zhang Pei
Published: September 2004

We tested the hypothesis that the antibody response to human factor IX in mice is controlled by genetic factors, especially histocompatibility antigens. Seven inbred mouse strains were immunized against human factor IX by adenoviral gene transfer or serial injections of human factor IX protein. A/J mice had the highest antibody response and 2 C57 mouse strains had the lowest response. We used the adenovirus vector to immunize 26 recombinant inbred mouse strains (AXB and BXA) derived from A/J and C57BL/6J mice and observed highly significant linkage (logarithmic odds [LOD] scores ∼4.8) for the polymorphic D17Mit62 marker that is 1 centimorgan (∼300 000 base pair [bp]) from the mouse major histocompatibility complex (MHC) locus (H-2). Experiments in mice with chimeric MHC genes indicated that class IaK or class II H-2 (or both) genes were critical, but other genes contributed to the antibody response. Polymorphic markers from chromosomes 1 and 10 that are near important immunoregulatory genes such as interleukin 10 and the interferon-γ gene show suggestive linkage (LOD scores of ∼2.3-2.6) to the factor IX antibody response. This study confirms the hypothesis that H-2 (and other) genes control factor IX antibody development in mice and suggests their potential importance for factor IX antibody development in humans with hemophilia B.
Low-dose total body irradiation causes clonal fluctuation of primate hematopoietic stem and progenitor cells
Authors: Laukkanen Mikko O. , Kuramoto Ken , Calmels Boris , Takatoku Masaaki , von Kalle Christof , Donahue Robert E. , Dunbar Cynthia E.
Published: September 2004

Due to high frequency of side effects caused by high-dose total body irradiation (TBI) the nonmyeloablative regimen together with cytotoxic agents is currently used especially for elderly patients. However, immediate and long-term effects of low-dose irradiation used in allogeneic transplantation on stem cells is less well known. We have studied the effect of low-dose 3 Gy TBI on the number of hematopoietic stem cell (HSC) clones contributing simultaneously to granulocyte production in rhesus macaque. The number of clones after 3 Gy TBI decreased markedly by 2 to 3 weeks after 3 Gy TBI, followed by a period of clonal instability, and recovery to almost pre–3 Gy TBI clonal diversity. The clones accounting for this recovery contributed before 3 Gy TBI, suggesting the profound initial impact of TBI was on a pool of progenitor cells, whereas most of the more primitive HSCs remained unaffected and were able to again contribute to hematopoiesis after recovery. Clonal fluctuation may indirectly suggest the presence of short-term/long-term HSC populations in rhesus macaque bone marrow as reported in a mouse model. The results indicate that even low-dose irradiation affects hematopoietic clonal dynamics and have implications for design of conditioning regimens for transplantation purposes.
Immune responses and tolerance to the RhD blood group protein in HLA-transgenic mice
Authors: Hall Andrew M. , Cairns Lindsay S. , Altmann Daniel M. , Barker Robert N. , Urbaniak Stanislaw J.
Published: September 2004

RhD is a major blood group and the most important target antigen in hemolytic disease of the newborn (HDN). The aims of this study were to establish a humanized mouse model of responses to the RhD protein and to test whether these could be prevented by the induction of immune tolerance. HLA-DR15 is a major restricting element for human T-helper (Th) cells specific for RhD protein, and expression of this HLA-DR transgene was found to confer on mice the ability to respond to immunization with purified RhD protein. Synthetic peptides containing dominant Th cell epitopes, previously identified from studies of human alloimmunized donors, were administered to the nasal mucosa of transgenic mice before immunization with purified RhD protein. Treatment with each of the 4 dominant peptides, RhD52-66, RhD97-111, RhD117-131, and RhD177-191, inhibited T-cell priming and prevented antibody responses to the RhD protein. The ability to induce such active tolerance offers the prospect of peptide immunotherapy as a replacement for passive immune globulin in the prophylaxis of HDN.
Minute numbers of contaminant CD8+ T cells or CD11b+CD11c+ NK cells are the source of IFN-γ in IL-12/IL-18-stimulated mouse macrophage populations
Authors: Schleicher Ulrike , Hesse Andrea , Bogdan Christian
Published: September 2004

Macrophages were reported to be strong producers of interferon γ (IFN-γ) after stimulation by interleukin 12 (IL-12) plus IL-18, which gave rise to a novel concept of auto-crine macrophage activation. Here, we show that peritoneal exudate and bone marrow-derived mouse macrophages generated by conventional techniques contain small quantities of CD11b+CD11c+CD31+DX5+NK1.1+ natural killer (NK) cells or CD3+CD8+TCRβ+ T cells, respectively. Intracellular cytokine staining, purification of macrophages by sorting, and the analysis of macrophages from alymphoid RAG2-/-γ-chain-/- mice revealed that the high amount of IFN-γ protein in the supernatants of unseparated IL-12/IL-18-stimulated macrophage populations originates exclusively from the contaminating lymphoid cells. Notably, IL-12/IL-18 still induced IFN-γ mRNA in highly purified macrophages from wild-type mice and in macrophages from RAG2-/-γ-chain-/- mice, whereas nuclear translocation of signal transducer and activator of transcription 4 (STAT4) and production of IFN-γ protein were no longer detectable. These results question the concept of autocrine macrophage activation by secreted IFN-γ, suggest differences in the expression of IFN-γ mRNA and protein between macrophages and lymphoid cells, and illustrate that the limited purity of most myeloid cell populations (≤ 98%) might lead to false conclusions.
Detection of somatic mosaicism and classification of Fanconi anemia patients by analysis of the FA/BRCA pathway
Authors: Soulier Jean , Leblanc Thierry , Larghero Jérôme , Dastot Hélène , Shimamura Akiko , Guardiola Philippe , Esperou Hélène , Ferry Christèle , Jubert Charlotte , Feugeas Jean-Paul , Henri Annie , Toubert Antoine , Socié Gérard , Baruchel André , Sigaux François , D'Andrea Alan D. , Gluckman Eliane
Published: September 2004

Fanconi anemia (FA) is characterized by congenital abnormalities, bone marrow failure, chromosome fragility, and cancer susceptibility. Eight FA-associated genes have been identified so far, the products of which function in the FA/BRCA pathway. A key event in the pathway is the monoubiquitination of the FANCD2 protein, which depends on a multiprotein FA core complex. In a number of patients, spontaneous genetic reversion can correct FA mutations, leading to somatic mosaicism. We analyzed the FA/BRCA pathway in 53 FA patients by FANCD2 immunoblots and chromosome breakage tests. Strikingly, FANCD2 monoubiquitination was detected in peripheral blood lymphocytes (PBLs) in 8 (15%) patients. FA reversion was further shown in these patients by comparison of primary fibro-blasts and PBLs. Reversion was associated with higher blood counts and clinical stability or improvement. Once constitutional FANCD2 patterns were determined, patients could be classified based on the level of FA/BRCA pathway disruption, as “FA core” (upstream inactivation; n = 47, 89%), FA-D2 (n = 4, 8%), and an unidentified downstream group (n = 2, 4%). FA-D2 and unidentified group patients were therefore relatively common, and they had more severe congenital phenotypes. These results show that specific analysis of the FA/BRCA pathway, combined with clinical and chromosome breakage data, allows a comprehensive characterization of FA patients.
Gi-independent macrophage chemotaxis to lysophosphatidylcholine via the immunoregulatory GPCR G2A
Authors: Yang Li V. , Radu Caius G. , Wang Li , Riedinger Mireille , Witte Owen N.
Published: September 2004

G2A is a G-protein–coupled receptor (GPCR) involved in immune regulation. Previous studies have shown that lysophosphatidylcholine (LPC), a bioactive lipid associated with atherosclerosis and autoimmunity, acts through G2A to induce diverse biologic effects. Production of LPC during cell apoptosis serves as a chemotactic signal for macrophage recruitment. Here we demonstrate that macrophage chemotaxis to LPC is dependent on G2A function. Wild-type but not G2A-deficient mouse peritoneal macrophages migrated toward LPC. RNAi-mediated knockdown of G2A in J774A.1 macrophages abolished LPC-induced chemotaxis, whereas overexpression of G2A significantly enhanced this process. Mutation of the conserved DRY motif of G2A resulted in loss of chemotaxis to LPC, suggesting a requirement for G-protein signaling. Unlike most GPCRs, including the chemokine receptors, coupling to Gi is not required for LPC/G2A-mediated chemotaxis, but coupling to Gq/11 and G12/13 is necessary as judged by inhibition with dominant negative forms of these alpha subunits or with regulators of G-protein signaling (RGS) constructs. Collectively, these data establish that pertussis toxin–insensitive G2A signaling regulates macrophage chemotaxis to LPC. Defects in this signaling pathway may be related to the pathogenesis of systemic autoimmune disease.
Adhesion of human T cells to antigen-presenting cells through SIRPβ2-CD47 interaction costimulates T-cell proliferation
Authors: Piccio Laura , Vermi William , Boles Kent S. , Fuchs Anja , Strader Carey A. , Facchetti Fabio , Cella Marina , Colonna Marco
Published: September 2004

Signal-regulatory proteins (SIRPs) are transmembrane glycoproteins belonging to the immunoglobulin (Ig) superfamily that are expressed in the immune and central nervous systems. SIRPα binds CD47 and inhibits the function of macrophages, dendritic cells, and granulocytes, whereas SIRPβ1 is an orphan receptor that activates the same cell types. A recently identified third member of the SIRP family, SIRPβ2, is as yet uncharacterized in terms of expression, specificity, and function. Here, we show that SIRPβ2 is expressed on T cells and activated natural killer (NK) cells and, like SIRPα, binds CD47, mediating cell-cell adhesion. Consequently, engagement of SIRPβ2 on T cells by CD47 on antigen-presenting cells results in enhanced antigen-specific T-cell proliferation.
What can we learn from noncoding regions of similarity between genomes?
Authors: Down Thomas A , Hubbard Tim JP
Published: September 2004

Background

In addition to known protein-coding genes, large amounts of apparently non-coding sequence are conserved between the human and mouse genomes. It seems reasonable to assume that these conserved regions are more likely to contain functional elements than less-conserved portions of the genome.

Methods

Here we used a motif-oriented machine learning method based on the Relevance Vector Machine algorithm to extract the strongest signal from a set of non-coding conserved sequences.

Results

We successfully fitted models to reflect the non-coding sequences, and showed that the results were quite consistent for repeated training runs. Using the learned models to scan genomic sequence, we found that they often made predictions close to the start of annotated genes. We compared this method with other published promoter-prediction systems, and showed that the set of promoters which are detected by this method is substantially similar to that detected by existing methods.

Conclusions

The results presented here indicate that the promoter signal is the strongest single motif-based signal in the non-coding functional fraction of the genome. They also lend support to the belief that there exists a substantial subset of promoter regions which share several common features including, but not restricted to, a relative abundance of CpG dinucleotides. This subset is detectable by a variety of distinct computational methods.
Simple statistical models predict C-to-U edited sites in plant mitochondrial RNA
Authors: Cummings Michael P , Myers Daniel S
Published: September 2004

Background

RNA editing is the process whereby an RNA sequence is modified from the sequence of the corresponding DNA template. In the mitochondria of land plants, some cytidines are converted to uridines before translation. Despite substantial study, the molecular biological mechanism by which C-to-U RNA editing proceeds remains relatively obscure, although several experimental studies have implicated a role for cis-recognition. A highly non-random distribution of nucleotides is observed in the immediate vicinity of edited sites (within 20 nucleotides 5' and 3'), but no precise consensus motif has been identified.

Results

Data for analysis were derived from the the complete mitochondrial genomes of Arabidopsis thaliana, Brassica napus, and Oryza sativa; additionally, a combined data set of observations across all three genomes was generated. We selected datasets based on the 20 nucleotides 5' and the 20 nucleotides 3' of edited sites and an equivalently sized and appropriately constructed null-set of non-edited sites. We used tree-based statistical methods and random forests to generate models of C-to-U RNA editing based on the nucleotides surrounding the edited/non-edited sites and on the estimated folding energies of those regions. Tree-based statistical methods based on primary sequence data surrounding edited/non-edited sites and estimates of free energy of folding yield models with optimistic re-substitution-based estimates of ~0.71 accuracy, ~0.64 sensitivity, and ~0.88 specificity. Random forest analysis yielded better models and more exact performance estimates with ~0.74 accuracy, ~0.72 sensitivity, and ~0.81 specificity for the combined observations.

Conclusions

Simple models do moderately well in predicting which cytidines will be edited to uridines, and provide the first quantitative predictive models for RNA edited sites in plant mitochondria. Our analysis shows that the identity of the nucleotide -1 to the edited C and the estimated free energy of folding for a 41 nt region surrounding the edited C are the most important variables that distinguish most edited from non-edited sites. However, the results suggest that primary sequence data and simple free energy of folding calculations alone are insufficient to make highly accurate predictions.
Complete mitochondrial genome sequence of Urechis caupo, a representative of the phylum Echiura
Authors: Boore Jeffrey L
Published: September 2004

Background

Mitochondria contain small genomes that are physically separate from those of nuclei. Their comparison serves as a model system for understanding the processes of genome evolution. Although hundreds of these genome sequences have been reported, the taxonomic sampling is highly biased toward vertebrates and arthropods, with many whole phyla remaining unstudied. This is the first description of a complete mitochondrial genome sequence of a representative of the phylum Echiura, that of the fat innkeeper worm, Urechis caupo.

Results

This mtDNA is 15,113 nts in length and 62% A+T. It contains the 37 genes that are typical for animal mtDNAs in an arrangement somewhat similar to that of annelid worms. All genes are encoded by the same DNA strand which is rich in A and C relative to the opposite strand. Codons ending with the dinucleotide GG are more frequent than would be expected from apparent mutational biases. The largest non-coding region is only 282 nts long, is 71% A+T, and has potential for secondary structures.

Conclusions

Urechis caupo mtDNA shares many features with those of the few studied annelids, including the common usage of ATG start codons, unusual among animal mtDNAs, as well as gene arrangements, tRNA structures, and codon usage biases.
Nestin-positive mesenchymal stem cells favour the astroglial lineage in neural progenitors and stem cells by releasing active BMP4
Authors: Wislet-Gendebien Sabine , Bruyère Françoise , Hans Grégory , Leprince Pierre , Moonen Gustave , Rogister Bernard
Published: September 2004

Background

Spontaneous repair is limited after CNS injury or degeneration because neurogenesis and axonal regrowth rarely occur in the adult brain. As a result, cell transplantation has raised much interest as potential treatment for patients with CNS lesions. Several types of cells have been considered as candidates for such cell transplantation and replacement therapies. Foetal brain tissue has already been shown to have significant effects in patients with Parkinson's disease. Clinical use of the foetal brain tissue is, however, limited by ethical and technical problems as it requires high numbers of grafted foetal cells and immunosuppression. Alternatively, several reports suggested that mesenchymal stem cells, isolated from adult bone marrow, are multipotent cells and could be used in autograft approach for replacement therapies.

Results

In this study, we addressed the question of the possible influence of mesenchymal stem cells on neural stem cell fate. We have previously reported that adult rat mesenchymal stem cells are able to express nestin in defined culture conditions (in the absence of serum and after 25 cell population doublings) and we report here that nestin-positive (but not nestin-negative) mesenchymal stem cells are able to favour the astroglial lineage in neural progenitors and stem cells cultivated from embryonic striatum. The increase of the number of GFAP-positive cells is associated with a significant decrease of the number of Tuj1- and O4-positive cells. Using quantitative RT-PCR, we demonstrate that mesenchymal stem cells express LIF, CNTF, BMP2 and BMP4 mRNAs, four cytokines known to play a role in astroglial fate decision. In this model, BMP4 is responsible for the astroglial stimulation and oligodendroglial inhibition, as 1) this cytokine is present in a biologically-active form only in nestin-positive mesenchymal stem cells conditioned medium and 2) anti-BMP4 antibodies inhibit the nestin-positive mesenchymal stem cells conditioned medium inducing effect on astrogliogenesis.

Conclusions

When thinking carefully about mesenchymal stem cells as candidates for cellular therapy in neurological diseases, their effects on resident neural cell fate have to be considered.
Early visual evoked potentials are modulated by eye position in humans induced by whole body rotations
Authors: Andersson Frédéric , Etard Olivier , Denise Pierre , Petit Laurent
Published: September 2004

Background

To reach and grasp an object in space on the basis of its image cast on the retina requires different coordinate transformations that take into account gaze and limb positioning. Eye position in the orbit influences the image's conversion from retinotopic (eye-centered) coordinates to an egocentric frame necessary for guiding action. Neuroimaging studies have revealed eye position-dependent activity in extrastriate visual, parietal and frontal areas that is along the visuo-motor pathway. At the earliest vision stage, the role of the primary visual area (V1) in this process remains unclear. We used an experimental design based on pattern-onset visual evoked potentials (VEP) recordings to study the effect of eye position on V1 activity in humans.

Results

We showed that the amplitude of the initial C1 component of VEP, acknowledged to originate in V1, was modulated by the eye position. We also established that putative spontaneous small saccades related to eccentric fixation, as well as retinal disparity cannot explain the effects of changing C1 amplitude of VEP in the present study.

Conclusions

The present modulation of the early component of VEP suggests an eye position-dependent activity of the human primary visual area. Our findings also evidence that cortical processes combine information about the position of the stimulus on the retinae with information about the location of the eyes in their orbit as early as the stage of primary visual area.
Long-distance transport of L-ascorbic acid in potato
Authors: Tedone Luigi , Hancock Robert D , Alberino Salvatore , Haupt Sophie , Viola Roberto
Published: September 2004

Background

Following on from recent advances in plant AsA biosynthesis there is increasing interest in elucidating the factors contributing to the L-ascorbic acid (AsA) content of edible crops. One main objective is to establish whether in sink organs such as fruits and tubers, AsA is synthesised in situ from imported photoassimilates or synthesised in source tissues and translocated via the phloem. In the current work we test the hypothesis that long-distance transport is involved in AsA accumulation within the potato tuber, the most significant source of AsA in the European diet.

Results

Using the EDTA exudation technique we confirm the presence of AsA in the phloem of potato plants and demonstrate a correlation between changes in the AsA content of source leaves and that of phloem exudates. Comparison of carboxyflourescein and AgNO3 staining is suggestive of symplastic unloading of AsA in developing tubers. This hypothesis was further supported by the changes in AsA distribution during tuber development which closely resembled those of imported photoassimilates. Manipulation of leaf AsA content by supply of precursors to source leaves resulted in increased AsA content of developing tubers.

Conclusion

Our data provide strong support to the hypothesis that long-distance transport of AsA occurs in potato. We also show that phloem AsA content and AsA accumulation in sink organs can be directly increased via manipulation of AsA content in the foliage. We are now attempting to establish the quantitative contribution of imported AsA to overall AsA accumulation in developing potato tubers via transgenic approaches.
Regulation of membrane fatty acid composition by temperature in mutants of Arabidopsis with alterations in membrane lipid composition
Authors: Falcone Deane L , Ogas Joseph P , Somerville Chris R
Published: September 2004

Background

A wide range of cellular responses occur when plants are exposed to elevated temperature, including adjustments in the unsaturation level of membrane fatty acids. Although membrane bound desaturase enzymes mediate these adjustments, it is unknown how they are regulated to achieve these specific membrane compositions. Furthermore, the precise roles that different membrane fatty acid compositions play in photosynthesis are only beginning to be understood. To explore the regulation of the membrane composition and photosynthetic function in response to temperature, we examined the effect of temperature in a collection of mutants with altered membrane lipid fatty acid composition.

Results

In agreement with previous studies in other species, the level of unsaturation of membrane fatty acids in Arabidopsis was inversely correlated with growth temperature. The time required for the membrane fatty acids to attain the composition observed at elevated temperature was consistent with the timing required for the synthesis of new fatty acids. Comparisons of temperature-induced fatty acid alterations in membranes were made among several Arabidopsis lines including wild-type Columbia, and the compositional mutants, fad5, fad6, act1 and double mutants, fad7 fad8 and act1 fad6. The results revealed key changes that occur in response to elevated temperature regardless of the specific mutations in the glycerolipid pathway, including marked decreases in trienoic fatty acids and consistent increases in unsaturated 16:0 and in dienoic 18:2 levels. Fluorescence measurements of various mutants indicated that photosynthetic stability as well as whole plant growth at elevated temperature is influenced by certain membrane fatty acid compositions.

Conclusions

The results of this study support the premise that defined proportions of saturated and unsaturated fatty acids in membrane lipids are required for photosynthetic thermostability and acclimation to elevated temperature. The results also suggest that changes in the membrane fatty acid composition brought about in response to temperature are regulated in such a way so as to achieve highly similar unsaturation levels despite mutations that alter the membrane composition prior to a high-temperature exposure. The results from examination of the mutant lines also suggest that interorganellar transfer of fatty acids are involved in mediating temperature-induced membrane alterations, and reveal steps in the fatty acid unsaturation pathway that appear to have key roles in the acclimatization of membranes to high temperature.
Psychosocial risk factors for obesity among women in a family planning clinic
Authors: Rohrer James E , Rohland Barbara M
Published: September 2004

Background

The epidemiology of obesity in primary care populations has not been thoroughly explored. This study contributes to filling this gap by investigating the relationship between obesity and different sources of personal stress, mental health, exercise, and demographic characteristics.

Methods

A cross-sectional survey using a convenience sample. Five hundred women who attended family planning clinics were surveyed and 274 provided completed answers to all of the questions analyzed in this study. Exercise, self-rated mental health, stress, social support, and demographic variables were included in the survey. Multiple logistic regression analysis was performed.

Results

After adjusting for mental health, exercise, and demographic characteristics of subjects, analysis of the data indicated that that being having a large family and receiving no support from parents were related to obesity in this relatively young low-income primary care sample, but self-reported stress and most types of social support were not significant.

Conclusion

Obesity control programs in primary care centers directed at low-income women should target women who have large families and who are not receiving support from their parents.
A failed RCT to determine if antibiotics prevent mastitis: Cracked nipples colonized with Staphylococcus aureus: A randomized treatment trial [ISRCTN65289389]
Authors: Amir Lisa Helen , Lumley Judith , Garland Suzanne M
Published: September 2004

Background

A small, non-blinded, RCT (randomised controlled trial) had reported that oral antibiotics reduced the incidence of mastitis in lactating women with Staphylococcus aureus (S. aureus)- colonized cracked nipples. We aimed to replicate the study with a more rigorous design and adequate sample size.

Methods

Our intention was to conduct a double-blind placebo-controlled trial to determine if an antibiotic (flucloxacillin) could prevent mastitis in lactating women with S. aureus-colonized cracked nipples. We planned to recruit two groups of 133 women with S. aureus-colonized cracked nipples.

Results

We spent over twelve months submitting applications to five hospital ethics committees and seven funding bodies, before commencing the trial. Recruitment to the trial was very slow and only ten women were randomized to the trial after twelve months, and therefore the trial was stopped early.

Conclusions

In retrospect we should have conducted a feasibility study, which would have revealed the low number of women in these Melbourne hospitals (maternity wards and breastfeeding clinics) with damaged nipples. The appropriate use of antibiotics for breastfeeding women with cracked nipples still needs to be tested.
Harpgophytum procumbens for osteoarthritis and low back pain: A systematic review
Authors: Gagnier Joel J , Chrubasik Sigrun , Manheimer Eric
Published: September 2004

Background

The objective of this review is to determine the effectiveness of Harpagophytum procumbens preparations in the treatment of various forms of musculoskeletal pain.

Methods

Several databases and other sources were searched to identify randomized controlled trials, quasi-randomized controlled trials, and controlled clinical trials testing Harpagophytum preparations in adults suffering from pain due to osteoarthritis or low back pain.

Results

Given the clinical heterogeneity and insufficient data for statistical pooling, trials were described in a narrative way, taking into consideration methodological quality scores. Twelve trials were included with six investigating osteoarthritis (two were identical trials), four low back pain, and three mixed-pain conditions.

Conclusions

There is limited evidence for an ethanolic Harpagophytum extract containing less than <30 mg harpagoside per day in the treatment of knee and hip osteoarthritis. There is moderate evidence of effectiveness for (1) the use of a Harpagophytum powder at 60 mg harpagoside in the treatment of osteoarthritis of the spine, hip and knee; (2) the use of an aqueous Harpagophytum extract at a daily dose of 100 mg harpagoside in the treatment of acute exacerbations of chronic non-specific low back pain; and (3) the use of an aqueous extract of Harpagophytum procumbens at 60 mg harpagoside being non-inferior to 12.5 mg rofecoxib per day for chronic non-specific low-back pain (NSLBP) in the short term. Strong evidence exists for the use of an aqueous Harpagophytum extract at a daily dose equivalent of 50 mg harpagoside in the treatment of acute exacerbations of chronic NSLBP.
Lycopene from two food sources does not affect antioxidant or cholesterol status of middle-aged adults
Authors: Collins JK , Arjmandi BH , Claypool PL , Perkins-Veazie P , Baker RA , Clevidence BA
Published: September 2004

Background

Epidemiological studies have reported associations between reduced cardiovascular disease and diets rich in tomato and/or lycopene. Intervention studies have shown that lycopene-containing foods may reduce cholesterol levels and lipid peroxidation, factors implicated in the initiation of cardiovascular disease. The objective of this study was to determine whether consumption of lycopene rich foods conferred cardiovascular protection to middle-aged adults as indicated by plasma lipid concentrations and measures of ex vivo antioxidants.

Methods

Ten healthy men and women consumed a low lycopene diet with no added lycopene (control treatment) or supplemented with watermelon or tomato juice each containing 20 mg lycopene. Subjects consumed each treatment for three weeks in a crossover design. Plasma, collected weekly was analyzed for total cholesterol, high density lipoprotein cholesterol (HDL-C) and triglyceride concentrations and for the antioxidant biomarkers of malondialdehyde formation products (MDA), plasma glutathione peroxidase (GPX) and ferric reducing ability of plasma (FRAP). Data were analyzed using Proc Mixed Procedure and associations between antioxidant and lipid measures were identified by Pearson's product moment correlation analysis.

Results

Compared to the control diet, the lycopene-containing foods did not affect plasma lipid concentrations or antioxidant biomarkers. Women had higher total cholesterol, HDL-C and triglyceride concentrations than did the men. Total cholesterol was positively correlated to MDA and FRAP while HDL-C was positively correlated to MDA and GPX. GPX was negatively correlated to triglyceride concentration.

Conclusions

The inclusion of watermelon or tomato juice containing 20 mg lycopene did not affect plasma lipid concentrations or antioxidant status of healthy subjects. However, plasma cholesterol levels impacted the results of MDA and FRAP antioxidant tests.
Variable Surface Glycoprotein RoTat 1.2 PCR as a specific diagnostic tool for the detection of Trypanosoma evansiinfections
Authors: Claes Filip , Radwanska Magda , Urakawa Toyo , Majiwa Phelix AO , Goddeeris Bruno , Büscher Philip
Published: September 2004

Background

Based on the recently sequenced gene coding for the Trypanosoma evansi (T. evansi) RoTat 1.2 Variable Surface Glycoprotein (VSG), a primer pair was designed targeting the DNA region lacking homology to other known VSG genes. A total of 39 different trypanosome stocks were tested using the RoTat 1.2 based Polymerase Chain Reaction (PCR).

Results

This PCR yielded a 205 bp product in all T. evansi and in seven out of nine T. equiperdum strains tested. This product was not detected in the DNA from T. b. brucei, T. b. gambiense, T. b. rhodesiense, T. congolense, T. vivax and T. theileri parasites. The Rotat 1.2 PCR detects as few as 10 trypanosomes per reaction with purified DNA from blood samples, i.e. 50 trypanosomes/ml.

Conclusion

PCR amplification of the RoTat 1.2 VSG gene is a specific marker for T. evansi strains, except T. evansi type B, and is especially useful in dyskinetoplastic strains where kDNA based markers may fail to amplify. Furthermore, our data support previous suggestions that some T. evansi stocks have been previously misclassified as T. equiperdum.
Incidence, risk factors and mortality of nosocomial pneumonia in Intensive Care Units: A prospective study
Authors: Alp Emine , Güven Muhammet , Yıldız Orhan , Aygen Bilgehan , Voss Andreas , Doganay Mehmet
Published: September 2004

To determine the frequency, risk factors and mortality of nosocomial pneumonia a prospective study was conducted in the intensive care units. In the study period, 2402 patients were included. The nosocomial pneumonia was defined according to the Centers for Disease Control Criteria. Overall, 163 (6.8%) of the patients developed nosocomial pneumonia and 75.5% (n = 123) of all patients with nosocomial pneumonia were ventilator-associated pneumonia. 163 patients who were admitted to the intensive care unit during the same period but had no bacteriologic or histologic evidence of pneumonia were used as a control group. The APACHE II score, coma, hypoalbuminemia, mechanical ventilation, tracheotomy, presence of nasogastric tube were found as independent risk factors. Crude and attributable mortality were 65% and 52.6%, respectively. The mortality rate was five times greater in the cases (OR: 5.2; CI 95%: 3.2–8.3). The mean length of stay in the intensive care unit and hospital in the cases were longer than controls (p < 0.0001). Patients requiring mechanical ventilation have a high frequency of nosocomial pneumonia.
Assessing response bias from missing quality of life data: The Heckman method
Authors: Sales Anne E , Plomondon Mary E , Magid David J , Spertus John A , Rumsfeld John S
Published: September 2004

Background

The objective of this study was to demonstrate the use of the Heckman two-step method to assess and correct for bias due to missing health related quality of life (HRQL) surveys in a clinical study of acute coronary syndrome (ACS) patients.

Methods

We analyzed data from 2,733 veterans with a confirmed diagnosis of acute coronary syndromes (ACS), including either acute myocardial infarction or unstable angina. HRQL outcomes were assessed by the Short-Form 36 (SF-36) health status survey which was mailed to all patients who were alive 7 months following ACS discharge. We created multivariable models of 7-month post-ACS physical and mental health status using data only from the 1,660 survey respondents. Then, using the Heckman method, we modeled survey non-response and incorporated this into our initial models to assess and correct for potential bias. We used logistic and ordinary least squares regression to estimate the multivariable selection models.

Results

We found that our model of 7-month mental health status was biased due to survey non-response, while the model for physical health status was not. A history of alcohol or substance abuse was no longer significantly associated with mental health status after controlling for bias due to non-response. Furthermore, the magnitude of the parameter estimates for several of the other predictor variables in the MCS model changed after accounting for bias due to survey non-response.

Conclusion

Recognition and correction of bias due to survey non-response changed the factors that we concluded were associated with HRQL seven months following hospital admission for ACS as well as the magnitude of some associations. We conclude that the Heckman two-step method may be a valuable tool in the assessment and correction of selection bias in clinical studies of HRQL.
Caring for family members with chronic physical illness: A critical review of caregiver literature
Authors: Lim Jung-won , Zebrack Brad
Published: September 2004

This article reviews 19 studies (1987–2004) on quality of life for family caregivers helping those with chronic physical illness. Here we explore the concepts of and instruments used to measure caregivers' quality of life. We were particularly interested in understanding stress-related variables and documenting factors influencing quality of life based on family stress theory. Findings show that various positive and negative terms equated with quality of life were used to measure them. Results indicate that stress-related variables as possible predictors influencing caregivers' quality of life include: patient and caregiver characteristics, stressors, stress appraisal, stress coping methods, and social support. Our recommendations touch upon applying theory for intervention, developing measurement, making operable the concepts for measuring, and the need for longitudinal and comprehensive study.
Imbalance in the health workforce
Authors: Zurn Pascal , Dal Poz Mario R , Stilwell Barbara , Adams Orvill
Published: September 2004

Imbalance in the health workforce is a major concern in both developed and developing countries. It is a complex issue that encompasses a wide range of possible situations. This paper aims to contribute not only to a better understanding of the issues related to imbalance through a critical review of its definition and nature, but also to the development of an analytical framework. The framework emphasizes the number and types of factors affecting health workforce imbalances, and facilitates the development of policy tools and their assessment. Moreover, to facilitate comparisons between health workforce imbalances, a typology of imbalances is proposed that differentiates between profession/specialty imbalances, geographical imbalances, institutional and services imbalances and gender imbalances.
Preoperative Sensitivity and Specificity for Early-Stage Ovarian Cancer When Combining Cancer Antigen CA-125II, CA 15-3, CA 72-4, and Macrophage Colony-Stimulating Factor Using Mixtures of Multivariate Normal Distributions
Authors: Skates Steven J. , Horick Nora , Yu Yinhua , Xu Feng-Ji , Berchuck Andrew , Havrilesky Laura J. , de Bruijn Henk W.A. , van der Zee Ate G.J. , Woolas Robert P. , Jacobs Ian J. , Zhang Zhen , Bast Robert C.
Published: September 2004

Purpose

In CA-125–based ovarian cancer screening trials, overall specificity and screening sensitivity of ultrasound after an elevated CA-125 exceeded 99.6% and 70%, respectively, thereby yielding a positive predictive value (PPV) exceeding 10%. However, sensitivity for early-stage disease was only 40%. This study aims to increase preoperative sensitivity for early-stage ovarian cancer while maintaining the annual referral rate to ultrasound at 2% by combining information across CA-125II, CA 15-3, CA 72-4, and macrophage colony-stimulating factor (M-CSF). For direct comparisons between marker panels, all sensitivity results correspond to a 98% fixed first-line specificity (referral rate 2%).

Patients and Methods

Logistic regression, classification tree, and mixture discriminant analysis (MDA) models were fit to a training data set of preoperative serum measurements (63 patients, 126 healthy controls) from one center. Estimates from the training set applied to an independent validation set (60 stage I to II patients, 98 healthy controls) from two other centers provided unbiased estimates of sensitivity.

Results

Preoperative sensitivities for early-stage disease of the optimal panels were 45% for CA-125II; 67% for CA-125II and CA 72-4; 70% for CA-125II, CA 72-4, and M-CSF; and 68% for all four markers (latter two results using MDA).

Conclusion

Efficiently combining information on CA-125II, CA 72-4, and M-CSF significantly increased preoperative early-stage sensitivity from 45% with CA-125II alone to 70%, while maintaining 98% first-line specificity. Screening trials with these markers using MDA followed by referral to ultrasound may maintain previously high levels of specificity and PPV, while significantly increasing early-stage screening sensitivity. MDA is a useful, biologically justified method for combining biomarkers.
Incidence and Predictors of Low Chemotherapy Dose-Intensity in Aggressive Non-Hodgkin's Lymphoma: A Nationwide Study
Authors: Lyman Gary H. , Dale David C. , Friedberg Jonathan , Crawford Jeffrey , Fisher Richard I.
Published: September 2004

Purpose

To assess the incidence of and risk factors for reduced relative dose-intensity (RDI) in patients treated with chemotherapy for aggressive non-Hodgkin's lymphoma (NHL).

Methods

A nationwide survey was conducted of 567 oncology practices with data extracted from the records of 4,522 patients with aggressive NHL treated with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP); CHOP-rituximab (CHOP-R); or cyclophosphamide, mitoxantrone, vincristine, and prednisone (CNOP). The primary outcome was the average RDI for each regimen based on both planned and reference standards. Other assessments included the incidence of febrile neutropenia and patterns of colony-stimulating factor (CSF) use, as well as the average RDI in high-risk subgroups.

Results

Dose reductions ≥ 15% occurred in 40% of patients and treatment delays ≥ 7 days occurred in 24% of patients, resulting in 53% and 48% of patients receiving an RDI less than 85% of the minimum six-cycle and National Comprehensive Cancer Network guideline standards, respectively. Reduced RDI was more prevalent in older patients, with 60% of patients older than 60 years receiving RDI less than 85%. Multivariate analysis identified several independent predictors for reduced RDI, including age older than 60 years, advanced disease stage, poor performance status, and no prophylactic CSF use. Age was no longer a significant risk factor in patients who received prophylactic CSF.

Conclusion

Patients with aggressive and potentially curable NHL treated with CHOP, CHOP-R, or CNOP frequently receive reduced RDI. Predictive models based on the risk factors identified for reduced RDI should enable the targeted use of appropriate supportive care, facilitating the delivery of full chemotherapy doses on schedule.
Expression of sialyl-Tn epitopes on β1 integrin alters epithelial cell phenotype, proliferation and haptotaxis
Authors: Clément Monique , Rocher Jézabel , Loirand Gervaise , Le Pendu Jacques
Published: September 2004

Sialyl-Tn (STn) is a tumor-associated carbohydrate antigen overexpressed in various carcinomas. To obtain its expression, murine carcinoma cells were transfected with the cDNA encoding ST6GalNAc I, a glycosyltransferase that acts exclusively on O-glycans. Overexpression of this enzyme led to the expected expression of cell surface STn epitopes. Surprisingly, the transfectants (STn+ cells) presented dramatic morphological changes and altered behavior. These STn+ cells lost the epithelial appearance of parental cells, became larger, more elongated and presented disorganized actin stress fibers. Additionally, their proliferation was impaired and their ability to migrate on fibronectin and hyaluronic acid was severely reduced. By contrast their adhesion on fibronectin remained unchanged. The major glycoprotein carrying the STn epitope was shown to be the integrin β1 subunit. Anti-STn antibodies could restore migration of STn+ cells on fibronectin. A constitutively active permeant form of RhoA (TAT-RhoAVal-14) also restored motility on fibronectin of STn+ cells as well as a parental STn-cellular phenotype. These observations indicate that overexpression of ST6GalNAc I leads to a major change of the O-glycosylation of the integrin β1 chain which in turn impairs the integrin-mediated signalling and leads to major alterations in morphology and cell behavior.
c-Cbl directs EGF receptors into an endocytic pathway that involves the ubiquitin-interacting motif of Eps15
Authors: de Melker Annemieke A. , van der Horst Gerda , Borst Jannie
Published: September 2004

c-Cbl associates with the activated EGF receptor before endocytosis. We here reveal that the capacity of c-Cbl to promote receptor internalization depends on its ubiquitin ligase activity, which functionally connects the EGF receptor to Eps15, a mediator of clathrin-coated pit formation. EGF-induced phosphorylation of Eps15, as well as recruitment of Eps15 to the plasma membrane and its co-localization with the EGF receptor in endosomes required the ubiquitin ligase activity of c-Cbl. This suggested that ubiquitin provides a direct or indirect link between the receptor and Eps15. Indeed, EGF-induced redistribution of Eps15 to the plasma membrane and endosomes depended on its ubiquitin-interacting motif. Upon over-expression, the ubiquitin-interacting motif abrogated the capacity of c-Cbl to promote EGF receptor endocytosis and only allowed receptor internalization via a route that lacked Eps15. Our findings disclose a novel function for the c-Cbl ubiquitin ligase and identify ubiquitin as a module that directs the EGF receptor into an endocytic pathway involving Eps15.
A novel partner forDictyosteliumfilamin is an α-helical developmentally regulated protein
Authors: Knuth Monika , Khaire Nandkumar , Kuspa Adam , Lu Si Jie , Schleicher Michael , Noegel, Angelika A.
Published: September 2004

The filamins are a family of highly homologous actincrosslinking proteins that stabilize three-dimensional actin networks, link them to membrane proteins and direct intracellular signaling reactions to the actin scaffold through interaction with various binding partners. Here, we describe the first Dictyostelium filamin-interacting protein to be isolated - FIP, a 229.8 kDa protein with two α-helical coiled coil domains. FIP was identified in a yeast two-hybrid screen using the rod domain of filamin as bait. FIP can also be coimmunoprecipitated with filamin from cellular extracts. Deletion analysis located the interaction domain of FIP to a C-terminal region; by contrast, in filamin rods, repeats 2-4 interacted with the recombinant FIP protein. The 7 kb transcript of FIP is upregulated during early development. Monoclonal antibodies raised against a bacterially expressed FIP polypeptide recognize a 230 kDa developmentally regulated protein in western blots. Immunofluorescence analysis shows a punctate staining pattern in the cytosol and, in cell fractionation experiments, FIP is mainly found in the cytosolic fraction. A fusion protein composed of GFP and the C-terminal part localizes to the plasma membrane and is associated with the cytoskeleton. Expression of the fusion protein affects development and influences the size of the multicellular aggregates and the phototactic behavior of slugs. Thus, FIP might provide a candidate link between the dynamic actin cytoskeleton and signal transduction events during the multicellular stages of Dictyostelium amoebae.