Search Results - (Author, Cooperation:J. Roper)

2016-03-05

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Animals ; Cell Count ; Cell Self Renewal/drug effects ; Cell Transformation, Neoplastic/*drug effects ; Colonic Neoplasms/*pathology ; Diet, High-Fat/*adverse effects ; Female ; Genes, APC ; Humans ; Intestines/*pathology ; Male ; Mice ; Obesity/chemically induced/pathology ; Organoids/drug effects/metabolism/pathology ; PPAR delta/metabolism ; Signal Transduction/drug effects ; Stem Cell Niche/drug effects ; Stem Cells/*drug effects/metabolism/*pathology ; beta Catenin/metabolism

2015-11-07

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Adenomatous Polyposis Coli Protein/genetics ; Animals ; Ascorbic Acid/administration & dosage/pharmacology/*therapeutic use ; Cell Line, Tumor ; Colorectal Neoplasms/*drug therapy/*genetics ; Dehydroascorbic Acid/metabolism ; Female ; Glucose Transporter Type 1/metabolism ; Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)/metabolism ; Glycolysis/drug effects ; Humans ; Mice ; Mice, Mutant Strains ; Mice, Nude ; Proto-Oncogene Proteins/*genetics ; Proto-Oncogene Proteins B-raf/*genetics ; Proto-Oncogene Proteins p21(ras)/genetics ; Reactive Oxygen Species/metabolism ; Xenograft Model Antitumor Assays ; ras Proteins/*genetics

1089-7550

AIP Digital Archive

Physics

Czochralski growth of cerium-doped Lu1.8Y0.2SiO5 (LYSO) from a 90/10 solution of Lu2SiO5 (LSO) and Y2SiO5 (YSO) is demonstrated. The alloyed scintillator retains the favorable growth properties of YSO and the desirable physical and optical scintillator properties of LSO. Radioluminescence, thermally stimulated luminescence, optical absorption, and lifetime measurements confirm the equivalence of LYSO and LSO optical properties. Advantages of LYSO Czochralski growth relative to LSO include reduced melting point, less propensity for formation of crystalline inclusions, lower cost of starting material, and easier incorporation of cerium into the host lattice. This material offers an attractive alternative to LSO for scintillator applications. © 2000 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Similarity among the thermally stimulated luminescence glow curves of undoped Lu2SiO5 and Ce3+-doped oxyorthosilicates possessing the monoclinic C2/c structure strongly suggests the luminescence traps are intrinsic in origin. They are most likely associated with the configuration of oxygen ions in the vicinity of not only the Ce3+ ion, as suggested in previous work, but also the host lanthanide ion. The optical absorption spectrum of pristine Lu2SiO5 shows the presence of intrinsic absorption centers that are enhanced upon x irradiation as seen in other oxides containing oxygen related point defects. © 1999 American Institute of Physics.

Electronic Resource

1089-7550

AIP Digital Archive

Physics

Temperature-dependent optical absorption of cerium-doped gadolinium oxyorthosilicate (Gd2SiO5:Ce) has been measured and analyzed for impurity-ion-lattice coupling parameters and oscillator strengths. Although the spectrum consists of overlapping Ce3+ bands and Gd3+ lines, two well-resolved Ce3+ bands with 10 K maxima at 3.32 eV (peak a) and 3.61 eV (peak b) are amenable to spectral analysis. These bands, previously assigned to Ce3+ ions occupying crystallographically inequivalent substitutional sites, are characterized by Gaussian line shapes and temperature-dependent half widths that are well described by the linear model of impurity-ion-lattice coupling. Huang–Rhys [Proc. R. Soc. A 204, 404 (1950)] parameters of peaks a and b are 22.7 and 5.7, respectively, indicating strong ion-lattice coupling, with vibrational frequencies 1.83×1013 s−1 (peak a) and 5.07×1013 s−1 (peak b). Peak b centroid is approximately temperature independent, but peak a centroid shifts to higher energy with increasing temperature. This dependence is adequately described by including higher-order coupling terms in the ion-lattice interaction, although crystal-field contributions cannot be excluded. Absorption band oscillator strengths, f, are calculated from Smakula's [Z. Phys. 59, 603 (1930)] formula and knowledge of cerium concentration for the two inequivalent sites. In the interval 10–300 K, peak a f values range from (9.8 to 26.8)×10−4 and peak b f values vary from (7.8 to 5.8)×10−3. From the known correlation between oscillator strength and metal-ion-ligand separation, we identify peaks a and b as the seven- and nine-oxygen-coordinated sites, respectively. © 2000 American Institute of Physics.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

A 34-year-old woman with secondary amenorrhoea and primary infertility became pregnant after treatment with clomiphene. She developed pre-eclampsia. Visual symptoms were experienced due to rapid enlargement of the anterior pituitary gland. The patient was delivered by Caesarean section. At subsequent craniotomy the patient was found to have haemorrhage into the pituitary gland, but histological examination of the pituitary tissue which was removed revealed no tumour tissue. One year after delivery the patient was still amenorrhoeic and had galactorrhoea with hyperprolactinaemia indicating that she probably had a small pituitary adenoma which was incompletely removed during neurosurgery.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

We have systematically studied the temperature- and magnetic field-dependent resistance in (La0.5Sr0.5)CoO3 (LSCO) films with various degrees of in-plane texturing using the biaxially oriented LSCO on CeO2/YSZ/SiO2/Si substrates. We find that the ferromagnetic transition temperature, Tc, is much the same in all samples while the resistive transition exhibits metallic behavior (dR/dT〉0) in the epitaxial LSCO to semiconducting behavior (dR/dT〈0) in the poorly textured LSCO. The magnetoresistance (MR) in the epitaxial LSCO on a LaAlO3 substrate displays two distinct regions; the low field hysteretic MR related to the magnetization hysteresis and the high field linear negative MR due to the suppression of spin fluctuations. In contrast, the MR in the biaxially textured LSCO sample shows only the hysteretic behaviors at low fields and no linear MR at high fields. Compared to the polycrystalline-doped LaMnO3 which shows an enhanced MR at low fields, the MR in the biaxially oriented LSCO does not exhibit such characteristics. We attribute this to the differences in the spin polarization between LSCO and the doped LaMnO3. © 1998 American Institute of Physics.

Electronic Resource

1077-3118

AIP Digital Archive

Physics

Superconducting YBa2Cu3O7−x (YBCO) thin films with a surface resistance of 0.86 mΩ at 10 GHz and 76 K have been grown on polycrystalline ferrite yttrium iron garnet (YIG) substrates. The chemical and structural mismatches between YBCO and YIG are solved by using a double buffer layer of biaxially oriented yttria-stabilized zirconia (YSZ) and CeO2, where YSZ is deposited by an ion-beam-assisted-deposition technique. The YBCO films are c axis oriented with an in-plane mosaic spread [full width at half maximum of an x-ray φ-scan on (103) reflection] of less than 8°. The films have a superconductive transition temperature above 88 K with a transition width less than 0.3 K, giving a critical current density above 106 A/cm2 in self field at 75 K. At 75 K in an external magnetic field of 1 T perpendicular to the film surface, the films maintain a critical current density over 2×105 A/cm2. © 1998 American Institute of Physics.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Breast milk contains many immunomodulatory factors (soluble CD14 (sCD14), IgA and cytokines) with the potential to influence infant immune development.Objective To determine if changes in breast milk ω-3 polyunsaturated fatty acid (n-3 PUFA) composition as a result of maternal dietary fish oil supplementation during pregnancy can modify levels of these immunological parameters in breast milk.Method In a randomized controlled trial, 83 atopic women received either 4 g fish oil capsules (containing 3.7 g n-3 PUFA) (n=40) or 4 g olive oil capsules (n=43) from 20 weeks gestation until delivery. Breast milk was collected 3 days post-partum and fatty acids were analysed by gas liquid chromatography and IgA, sCD14 and cytokines (IL-5, IL-6, IL-10, TNF-α and IFN-γ) were quantitated by ELISA or time resolved fluorescence (TRF).Results ω-3 docosahexaenoic acid (DHA; 22:6n-3) and eicosapentaenoic acid (EPA; 20:5n-3) levels were significantly higher (P〈0.001) in breast milk from women supplemented with fish oil (n=33, DHA mean 1.15%, SD 0.47% and EPA mean 0.16%, SD 0.07%) than in samples from the control group (n=40, DHA mean 0.50%, SD 0.17% and EPA mean 0.05%, SD 0.02%). Breast milk arachidonic acid (AA; 20:4n-6) levels were significantly lower (P=0.045) in the fish oil group (mean 0.55%, SD 0.12%) compared with the control group (mean 0.61%, SD 0.14%). Breast milk IgA was positively correlated with DHA (P=0.046) and 22:5n-3 (P=0.003), but inversely correlated with linoleic acid (LA; 18:2n-6) (P=0.034). Levels of sCD14 were also positively correlated with 22:5n-3 (P=0.009). Cytokines involved in IgA synthesis (IL-10 and IL-6) were also significantly correlated with both IgA and n-3 PUFA levels, although there were no differences in the levels of breast milk IgA, sCD14 or cytokines between study groups.Conclusion Supplementation with fish oil during pregnancy significantly alters early post-partum breast milk fatty acid composition. ω-3 PUFA levels were positively associated with IgA and sCD14 levels, suggesting a relationship between fatty acid status and mucosal immune function.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background Maternal allergy confers stronger allergy risk (than paternal allergy) suggesting that maternal patterns of immune response can directly influence immune development in offspring. Women prone to allergic immune responses to allergens may also have altered immune responses to other antigens including fetal antigens.Objective This exploratory study examines relationships between maternal immune responses to fetal antigens and the subsequent risk of allergy.Methods Mononuclear cells (MNC) were collected from 36 mother–infant pairs to compare maternal (and fetal) cellular immune responses to alloantigens (fetal, maternal or unrelated donor [URD]), and allergens in allergic (18 pairs) and non-allergic (18 pairs) mothers. Thirty children had documented allergic outcomes at 6 years of age.Results In this population, allergic outcomes in the offspring were associated more strongly with materno-fetal immune interactions than with a maternal family history of allergy. Specifically, allergic disease at 6 years of age was associated with significantly higher maternal responses to fetal alloantigens (lymphoproliferation, P=0.008; IL-13, P=0.02 and IFN-γ, P=0.015), whereas associations with maternal allergy did not reach significance (P=0.07). Fetal IFN-γ alloantigen responses were significantly correlated with the degree of human lymphocyte antigen (HLA) mismatch (maternal HLA class II antibodies) (τ=0.3, P=0.03). The capacity of the fetus to produce IL-13 (τ=0.4, P=0.001) and IL-10 (τ=0.3, P=0.029) was directly related to the level of these cytokines produced by the mother in response to fetal antigens. Allergic mothers showed a non-significant trend for stronger lymphoproliferation to fetal alloantigens. The number of previous pregnancies (gravidity) was associated with stronger maternal responses to fetal alloantigens, as shown by lymphoproliferation (Kendall τ=0.3, P=0.04) and IFN-γ (τ=0.3, P=0.04) synthesis, but did not affect fetal responses to the various stimuli.Conclusions Maternal responses to fetal antigens were related to fetal immune responses and subsequent allergy. This novel observation suggests that events at the materno-fetal interface have an important influence on early immune development and should be investigated further.

Electronic Resource

1365-2222

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Background The T-helper type 1 (Th1) trophic properties of bacterial cytosine–phosphate–guanine (CpG) motifs have made them logical adjuvants both for the suppression of Th2-mediated allergic disease in early life and for promoting vaccine responses in neonates who have relatively immature Th1 function. However, little is known about their effects on immature immune responses in this period.Objectives To compare the effects of CpG on adult and neonatal cellular immune responses to various stimuli.Methods The immune responses of mononuclear cells (MC) derived from neonates (n=25) and their mothers (n=25) were compared in vitro. These were stimulated with house dust mite (HDM), CpG B, CpG C, non-CpG oligodeoxynucleotides (ODN) or diphtheria toxoid (DT) in optimized conditions. In parallel cultures, CpGs were combined with HDM or DT antigens to assess the effect of the various ODN on these antigen-specific responses. Lymphoproliferation and cytokine responses IL-13, IFN-γ, IL-6, IL-10, TNF-α) were measured for all of the cultures described above.Results Although neonates showed attenuated lymphoproliferation to CpG, the production of antigen-presenting cell-derived cytokines such as IL-6 and IL-10 and the up-regulation of major histocompatibility complex class II (HLA-DR) were detected at adult levels. T cell-derived cytokines (IL-13 and IFN-γ) were not detectable in response to CpG alone. Most neonates also failed to produce detectable IFN-γ to HDM or DT (unlike adults), but readily produced IL-13 to these stimuli. The addition of CpG resulted in an increase in neonatal IFN-γ production in response to HDM (P=0.011) and a similar but non-significant trend with DT. However, rather than inhibiting Th2 IL-13 responses, the addition of CpGs was associated with a significant increase in the IL-13 responses to HDM (P=0.016) and DT (P=0.03), effects not seen in adults.Conclusions This study provides further evidence that neonatal MC responses to CpG are functionally different from adults, and do not show clear Th1 polarization. The CpG associated increase in Th2 responses may reflect a potentiation of the normal neonatal Th2 propensity, or non-specific activation of neonatal MC.

Electronic Resource

1095-8649

Blackwell Publishing Journal Backfiles 1879-2005

Biology

Injection of extracts derived from adult caligid copepods induced a partial immunity to Lepeophtheirus salmonis in Atlantic salmon. Antigens were derived from the supernatant of adult lice extracts and were partially purified by Con A affinity chromatography. The antigens were also present in the pellet derived from adult lice extracts, Immunohistochemistry showed that antibodies present in the serum of rats immunized with the Con A purified extract bound predominantly to the gut of L. salmonis. Components of apparent sizes 〉 205 000, 165 000, 133 000, 130 000, 125 000, 114 000, 110 000, 96 000, 82 000, 78 000, 65 000, 46 000, 35 000, 31 000 and 〈 29 000 were present in the extract. Although the numbers of attached lice were initially higher on those fish in the immunized group, throughout the course of the challenge experiment the total numbers of lice did not vary greatly between the immunized or control groups of fish. Initially, an overall average of about 17 attached stages were recorded from each fish sampled and by the end of the experiment this figure had fallen to about five adult lice per fish. However, compared with control fish fewer gravid female lice were present on immunized fish and furthermore these lice possessed fewer eggs (P〈0.01). No major differences in egg hatching success were recorded. Further exploitation of this would require the isolation and purification of the antigens responsible for the observed effects. The possibilities for the development of a salmon louse vaccine are promising.

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] In vertebrate tissues it is difficult to make sure that a tissue has a population of nuclei homogeneous in respect of the number of chromosome sets. Therefore we have thought it of use to investigate the deoxyribonucleic acid content of conidia of diploid and haploid strains of Aspergillus ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Further support for this interpretation has now been obtained by the recovery, within a single diploid nucleus, of the reciprocal products of mitotic crossing-over. The technique used was based on recombination between alloles making use of the well-known position effect3 usually shown by allelic ...

Electronic Resource

0301-0104

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Chemistry and Pharmacology

Physics

Electronic Resource

0955-0674

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] A working hypothesis for the deliberate search for linkage10 is that close linkage might be expected between some of the genes acting on any one series of milli-micromolar biochemical reactions11. A first deliberate search for linkage prompted by this working hypothesis has led to positive ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] GENETIC analysis resolves the genome into inkage groups and the linkage groups into loci which can be graphically represented as arranged in a line. Each linkage group has its structural basis in a chromosome and each locus in a small segment of a chromosome. In the case, more unique than rare, of ...

Electronic Resource

1476-4687

Nature Archives 1869 - 2009

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

[Auszug] Fig. 1. Yellow sectors, produced by a duplication strain with green. conidia, following deletion of the dominant y+ allele: a, control after 7 days; b, grown on 300 µg/ml. trypan blue for 9 days. Fig. 2. Genotypes of strains used. Linkage groups I and II are shown by unbroken and broken ...

Electronic Resource

1420-9071

Springer Online Journal Archives 1860-2000

Biology

Medicine

Résumé En exposant aux vapeurs de camphre un mycélium de l'Aspergillus midulans hétérocaryotique pour deux types de noyaux génétiquement marqués, on a obtenu des noyaux diploïdes hétérozygotes. Il est probable que ces noyaux diploïdes sont produits par l'inclusion dans un seul noyau de deux groupes haploïdes de chromosomes-fils résultant de la division de deux noyaux de types différents. On a réalisé ainsi une sorte de caryogamie artificielle. Des souches diploïdes sont obtenues par l'isolement au micromanipulateur de conidies uninuclées diploïdes. On peut vérifier le fait que les souches sont diploïdes en observant 1 leur phénotypes; 2 le nombre de chromosomes; 3 la ségrégation et la recombinaison des gènes dans les ascospores; 4 la recombinaison somatique; 5 le diamètre des conidies.

Electronic Resource