Home About us Contact
|
Home About us Contact | ||
|
|
||
Notable Increase (notable + increase)
Selected AbstractsExpression patterns of hormones, signaling molecules, and transcription factors during adenohypophysis development in the chick embryoDEVELOPMENTAL DYNAMICS, Issue 4 2010Nicole Parkinson Abstract The chick embryo is an ideal model to study pituitary cell-type differentiation. Previous studies describing the temporal appearance of differentiated pituitary cell types in the chick embryo are contradictory. To resolve these controversies, we used RT-PCR to define the temporal onset and in situ hybridization and immunohistochemistry to define the spatial localization of hormone expression within the pituitary. RT-PCR detected low levels of Fsh, (gonadotropes) and Pomc (corticotropes, melanotropes) mRNA at E4 and Gh (somatotropes), Prl (lactotropes), and Tsh, (thyrotropes) mRNA at E8. For all hormones, sufficient accumulation of mRNA and/or protein to permit detection by in situ hybridization or immunohistochemistry was observed ,3 days later and in all cases corresponded to a notable increase in RT-PCR product. We also describe the expression patterns of signaling (Bmp2, Bmp4, Fgf8, Fgf10, Shh) and transcription factors (Pitx1, Pitx2, cLim3) known to be important for pituitary organogenesis in other model organisms. Developmental Dynamics 239:1197,1210, 2010. © 2010 Wiley-Liss, Inc. [source] Change over 70 years in a southern California chaparral community related to fire historyJOURNAL OF VEGETATION SCIENCE, Issue 5 2004Janet Franklin Abstract: Question: What changes in species composition and cover have occurred in chaparral as a function of fire history across an ecoregion? Location: San Diego County, California, USA. Methods: Stands in which 40 mid-elevation chaparral vegetation plots (each 400 m2 in area) were located in the 1930s were resurveyed in 2001. We stratified the stands into Infrequently versus Frequently burned (0,1 versus 2 or more fires recorded in the 91-yr period), and Immature versus Mature (31 yr versus >31 yr since last fire), resulting in four groups. Ten stands were randomly selected from each of these groups for survey. Results: There were no major shifts in life form composition, e.g., live oak trees were not invading chaparral that had experienced little or no fire, nor were subshrubs or herbaceous species replacing shrubs in areas that had experienced more frequent fires. However, there was a notable increase in the frequency of the subshrub Eriogonum fasciculatum across all fire history groups. In the mature stands with infrequent fire, average cover of resprouting shrubs increased (from 72 to 91%) and cover of obligate seeding shrubs (species with fire-cued germination) decreased (from 21 to 6%) significantly. Mature stands with frequent fire showed a significant decrease in resprouter cover (from 87 to 80%) and increase in obligate seeders (from 10 to 16%). Conclusions: While the tremendous changes in land use in southern California have been predicted to cause shifts in chaparral composition, these shifts are difficult to detect because species longevity and fire cycles are on the order of decades to a century. In this study, the expected trends could only be detected in groups that were mature at the time of the second survey. [source] Solid-state NMR spectroscopy of the quadrupolar halogens: chlorine-35/37, bromine-79/81, and iodine-127MAGNETIC RESONANCE IN CHEMISTRY, Issue 4 2006David L. Bryce Abstract A thorough review of 35/37Cl, 79/81Br, and 127I solid-state nuclear magnetic resonance (SSNMR) data is presented. Isotropic chemical shifts (CS), quadrupolar coupling constants, and other available information on the magnitude and orientation of the CS and electric field gradient (EFG) tensors for chlorine, bromine, and iodine in diverse chemical compounds is tabulated on the basis of over 200 references. Our coverage is through July 2005. Special emphasis is placed on the information available from the study of powdered diamagnetic solids in high magnetic fields. Our survey indicates a recent notable increase in the number of applications of solid-state quadrupolar halogen NMR, particularly 35Cl NMR, as high magnetic fields have become more widely available to solid-state NMR spectroscopists. We conclude with an assessment of possible future directions for research involving 35/37Cl, 79/81Br, and 127I solid-state NMR spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd. [source] "New" Mainstream SLA Theory: Expanded and EnrichedMODERN LANGUAGE JOURNAL, Issue 5 2007MERRILL SWAIN How have the ideas raised by Firth and Wagner (1997) influenced the construction of second language acquisition (SLA) theories? In this article, we take the position that prior to and since 1997, there was and has been a notable increase in SLA research and theory that prioritizes sociocultural and contextual factors in addition to acknowledging individual agency and multifaceted identities. This article focuses on 4 major influences on a growing body of SLA research: sociocultural theory of mind, situated learning, poststructural theories, and dialogism. We highlight aspects of these perspectives that have been used in SLA theory, and provide examples of research that illustrate the richness and complexity of constructs such as languaging, legitimate peripheral participation, subjectivity, and heteroglossia. These perspectives and constructs address Firth and Wagner's call for a reconceptualization of SLA by offering alternative understandings of language and language learning. [source] "New" Mainstream SLA Theory: Expanded and EnrichedMODERN LANGUAGE JOURNAL, Issue 2007MERRILL SWAIN How have the ideas raised by Firth and Wagner (1997) influenced the construction of second language acquisition (SLA) theories? In this article, we take the position that prior to and since 1997, there was and has been a notable increase in SLA research and theory that prioritizes sociocultural and contextual factors in addition to acknowledging individual agency and multifaceted identities. This article focuses on 4 major influences on a growing body of SLA research: sociocultural theory of mind, situated learning, poststructural theories, and dialogism. We highlight aspects of these perspectives that have been used in SLA theory, and provide examples of research that illustrate the richness and complexity of constructs such as languaging, legitimate peripheral participation, subjectivity, and heteroglossia. These perspectives and constructs address Firth and Wagner's call for a reconceptualization of SLA by offering alternative understandings of language and language learning. [source] CP43,, the isiA Gene Product, Functions as an Excitation Energy Dissipator in the Cyanobacterium Synechococcus sp.PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 3 2001PCC 794 ABSTRACT Under conditions of iron deficiency certain cyanobacteria induce a chlorophyll (Chl)-binding protein, CP43,, which is encoded by the isiA gene. We have previously suggested that CP43, functions as a nonradiative dissipator of light energy. To further substantiate its functional role an isiA overexpression construct was introduced into the genome of a cyanobacterium Synechococcus sp. PCC 7942 (giving isiAoe cells). The presence of functional CP43, in isiAoe cells was confirmed by Western blot as well as by the presence of a characteristic blueshift of the red Chl a absorption peak and a notable increase in the 77 K fluorescence peak at 685 nm. Compared to wild-type cells isiAoe cells, with induced CP43,, had both smaller functional antenna size and decreased yields of room temperature Chl fluorescence at various light irradiances. These observations strongly suggest that isiAoe cells, with induced CP43,, have an increased capacity for dissipating light energy as heat. In agreement with this hypothesis isiAoe cells were also more resistant to photoinhibition of photosynthesis than wild-type cells. Based on these results we have further strengthened the hypothesis that CP43, functions as a nonradiative dissipator of light energy, thus protecting photosystem II from excessive excitation under iron-deficient conditions. [source] Effects of water exchange and abiotic factors on zooplankton and epibenthic fauna in shrimp pondsAQUACULTURE RESEARCH, Issue 14 2006Frank E Coman Abstract Assemblages of zooplankton and epibenthic invertebrates were collected from a commercial Penaeus monodon (Fabricius) pond at fortnightly intervals over an entire grow-out season. The pond inlet and outlet water were also sampled intensively over three 1-week periods throughout the season. Before stocking the ponds with shrimp postlarvae, copepods dominated the zooplankton. Immediately after the ponds were stocked, there was a rapid decline in zooplankton numbers, particularly the dominant larger copepods, suggesting heavy predation by shrimp postlarvae. For the rest of the season, barnacle nauplii were the dominant zooplankton component in the pond. Pond water exchanges had little detectable influence on the composition or density of the zooplankton assemblage. Instead, the dominance of barnacle nauplii appeared to have been maintained by steady recruitment due to barnacle reproduction in the pond. While changes in the biomass of pond zooplankton were not correlated with physico-chemical characteristics, changes in density were positively correlated with temperature, and negatively correlated with pH, dissolved oxygen and secchi disc readings. Epibenthic faunal density peaked at the end of the season, while the biomass peaked during the middle part of the season. Sergestids (Acetes sibogae Hansen) were the most abundant epibenthic taxa. No correlations were found between physico-chemical parameters and epibenthic fauna biomass or density. Abundances of epibenthic fauna were not related to zooplankton densities, suggesting that trophic interactions between these assemblages is not important. No Acetes were captured in samples of outlet water, and only on a single occasion were large numbers captured in the inlet water; after this, there was a notable increase in the number of Acetes in the pond. This evidence, together with the lack of an increase in the size of Acetes during the season, suggests that water exchange is an important but unpredictable source of recruitment of epibenthic fauna into the pond. The results emphasize the benefits of ensuring that appropriate zooplankton assemblages have been introduced into the ponds, when they are filled, to support the shrimp immediately after stocking. This will depend on the initial inoculum and may be difficult to manipulate with water exchanges once established. Assemblages of epibenthic fauna appear more likely to change with exchanges and may need to be monitored across the season, particularly if their presence reduces production through adverse impacts such as competition with postlarvae, introduction of disease or deteriorated water quality. [source] Urinary CD4+ effector memory T cells reflect renal disease activity in antineutrophil cytoplasmic antibody,associated vasculitisARTHRITIS & RHEUMATISM, Issue 9 2009Wayel H. Abdulahad Objective Numbers of circulating CD4+ effector memory T cells are proportionally increased in patients with proteinase 3 antineutrophil cytoplasmic antibody,associated vasculitis (AAV) whose disease is in remission and are decreased during active disease, which presumably reflects their migration toward sites of inflammation. Since renal infiltrating cells may appear in urine, we investigated the presence of CD4+ effector memory T cells in urinary sediment as a reflection of renal disease activity in AAV. Methods CD4+ effector memory (CD45RO+CCR7,CD3+CD4+) T cells were quantitated in the urine and peripheral blood of patients with AAV with renal involvement (n = 33), patients with AAV without renal involvement (n = 18), patients with AAV whose disease was in remission (n = 29), and patients with active disease (n = 22), using 4-color flow cytometric analysis. Numbers and percentages of urine CD4+ effector memory T cells in 12 patients with AAV with active renal disease were obtained over several weeks of followup during remission induction. Results A notable increase in urine CD4+ effector memory T cell numbers was observed in patients with active renal AAV compared with patients whose disease was in remission and patients with active disease without renal involvement. The increase in these cells in the urine of patients with active renal AAV was accompanied by a reciprocal decrease in these cells in peripheral blood. Results from followup analysis showed a clear reduction in urine CD4+ effector memory T cells following treatment. Moreover, a negative correlation was observed between percentages of circulating and urine CD4+ effector memory T cells, consistent with their migration toward sites of inflammation. Conclusion Our findings indicate that the presence of CD4+ effector memory T cells in urine reflects renal involvement in AAV. Flow cytometric analysis of these cells in urine may contribute to assessing renal disease activity in patients with AAV. [source] Novel Controlling Mechanism of the Oxygen Affinity in Myoglobin With Isomeric PorphyrinsARTIFICIAL ORGANS, Issue 2 2009Saburo Neya Abstract The biological function of the core modified porphyrin isomers such as porphycene, corrphycene, and hemiporphycene was examined. The iron complexes stoichiometrically coupled with apomyoglobin to afford stable holoproteins. The oxygen affinity of the reconstituted myoglobins (Mbs) changed over a 60 000-fold range depending on the molecular structure of the prosthetic groups. For instance, a corrphycene with electronegative substituents to the bipyrrole part reduced the oxygen affinity of Mb to P50 = 300 mm Hg while the porphycene-substituted Mb exhibited a P50 = 0.005 mm Hg. A notable increase in the oxygen delivery capacity of the corrphycene-substituted Mb was explained on the basis of the trapezoidal corrphycene shape that stabilizes the iron displacement from the macrocycle plane toward the proximal histidine. The above observations demonstrate that the core modified heme isomers serve as novel molecular tools to regulate the oxygen affinity of Mb. [source] Human ovarian carcinoma cells: Histone deacetylase inhibitors exhibit antiproliferative activity and potently induce apoptosisCANCER, Issue 12 2004Noriyuki Takai M.D., Ph.D. Abstract BACKGROUND Histone deacetylase inhibitors (HDACIs) can inhibit proliferation, stimulate apoptosis, and induce cell cycle arrest in malignant cells. METHODS The authors investigated the effects of four HDACIs on nine ovarian carcinoma cell lines in vitro and in vivo. Ovarian carcinoma cells were treated with a variety of HDACIs, and their effects on cell growth, the cell cycle, apoptosis, and related events were investigated. The ability of valproic acid (VPA) to inhibit the growth of ovarian tumors in immunodeficient mice was also assessed. RESULTS Clonogenic assays showed that all ovarian carcinoma cell lines were sensitive to the growth-inhibitory effects of the HDACIs. Cell cycle analysis indicated that their exposure to HDACIs decreased the proportion of cells in S phase and increased the proportion of cells in the G0/G1 and/or G2/M phases of the cell cycle. Terminal deoxynucleotidyltransferase-mediated uridine triphosphate end-labeling assays demonstrated that HDACIs induced apoptosis, which occurred in concert with alterations in the expression of genes related to apoptosis, cell growth, and malignant phenotype, including the activation of caspase-9 and caspase-3. Chromatin immunoprecipitation analysis revealed a notable increase in levels of acetylated histones associated with the p21 promoter after treatment with suberoylanilide bishydroxamine. In addition, in experiments involving nude mice, VPA significantly inhibited human ovarian tumor growth without toxic side effects. CONCLUSIONS The results of the current study suggest that HDACIs may be particularly effective in the treatment of ovarian tumors. Cancer 2004. © 2004 American Cancer Society. [source] Head-to-Head Right-Handed Cross-Links of the Antitumor-Active Bis(,- N,N,-di- p -tolylformamidinato)dirhodium(II,II) Unit with the Dinucleotides d(GpA) and d(ApG)CHEMISTRY - A EUROPEAN JOURNAL, Issue 32 2008Helen Abstract Reactions of cis -[Rh2(DTolF)2(NCCH3)6](BF4)2 with the dinucleotides d(GpA) and d(ApG) proceed to form [Rh2(DTolF)2{d(GpA)}] and [Rh2(DTolF)2{d(ApG)}], respectively, with bridging purine bases spanning the Rh,Rh unit in the equatorial positions. Both dirhodium adducts exhibit head-to-head (HH) arrangement of the bases, as indicated by the presence of H8/H8 NOE cross-peaks in the 2D ROESY NMR spectra. The guanine bases bind to the dirhodium core at positions N7 and O6, a conclusion that is supported by the absence of N7 protonation at low pH,values and the notable increase in the acidity of the guanine N1H sites (pKa,7.4 in 4:1 CD3CN/D2O), inferred from the pH-dependence titrations of the guanine H8 proton resonances. In both dirhodium adducts, the adenine bases coordinate to the metal atoms through N6 and N7, which induces stabilization of the rare imino tautomer of the bases with a concomitant substantial decrease in the basicity of the N1H adenine sites (pKa,7.0,7.1 in 4:1 CD3CN/D2O), as compared to the imino form of free adenosine. The presence of the adenine bases in the rare imino form is further corroborated by the observation of DQF-COSY H2/N1H and ROE N1H/N6H cross-peaks in the 2D NMR spectra of [Rh2(DTolF)2{d(GpA)}] and [Rh2(DTolF)2{d(ApG)}] in CD3CN at ,38,°C. The 2D NMR spectroscopic data and the molecular modeling results suggest the presence of right-handed variants, HH1R, in solution for both adducts (HH1R refers to the relative base canting and the direction of propagation of the phosphodiester backbone with respect to the 5, base). Complete characterization of [Rh2(DTolF)2{d(GpA)}] and [Rh2(DTolF)2{d(ApG)}] by 2D,NMR spectroscopy and molecular modeling supports anti- orientation of the sugar residues for both adducts about the glycosyl bonds as well as N- and S-type conformations for the 5,- and 3,-deoxyribose residues, respectively. [source] Defect of protective immunity to Schistosoma mansoni infection in Mongolian gerbils involves limited recruitment of dendritic cells in the vaccinated skinPARASITE IMMUNOLOGY, Issue 12 2001H. Sato In Mongolian gerbils, Meriones unguiculatus, the attenuated Schistosoma mansoni vaccine, is known to induce marginal or no resistance to a homologous infection. To clarify the base of defective acquisition of the resistance, we have focused on the induction phase of protective immunity to S. mansoni, i.e. cellular responses in the skin and skin-draining lymph nodes (SLN). Percutaneous exposure to normal or ultraviolet (18mJ/cm2)-attenuated cercariae induced comparable increases in SLN leucocyte counts, in contrast to other attenuated schistosome vaccine models in rodents where attenuated parasites induce more notable increases in SLN leucocyte counts than normal ones. Using serial sections, it was demonstrated that greater numbers of attenuated larvae remained for a longer period in the exposed skin than normal ones. Correlated with cellular responses in the SLN, attenuated and normal schistosomes elicited a comparable degree of response of epidermal Langerhans' cells/putative dermal dendritic cells that were visualized by immunohistochemistry using a monoclonal antibody to a gerbil major histocompatibility complex class II molecule (HUSM-M.g.30). It is speculated that in Mongolian gerbils limited recruitment of dendritic cells around attenuated S. mansoni larvae, at least partially, contribute to defective induction of protective immunity by the attenuated vaccine. [source] | |||||||||||||||||||