bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dehydroascorbate Reductase Affects Leaf Growth, Development, and Function
Authors: Chen Zhong , Gallie Daniel R. 
Published: August 2006

Abstract
Ascorbic acid (Asc) is a major antioxidant in plants that detoxifies reactive oxygen species (ROS) and maintains photosynthetic function. Expression of dehydroascorbate reductase (DHAR), responsible for regenerating Asc from an oxidized state, regulates the cellular Asc redox state, which in turn affects cell responsiveness and tolerance to environmental ROS. Because of its role in Asc recycling, we examined whether DHAR is important for plant growth. Suppression of DHAR expression resulted in a preferential loss of chlorophyll a, a lower steady state of Rubisco as measured by the amount of the large subunit of Rubisco (RbcL), and a lower rate of CO2 assimilation. As a consequence, a slower rate of leaf expansion and reduced foliar dry weight were observed. In addition, an accelerated rate of loss of chlorophyll, RbcL, light-harvesting complex II, and photosynthetic functioning was observed in mature leaves, resulting in premature leaf aging. Reduced growth rate as measured by plant height and leaf number was consistent with the DHAR-mediated reduction of photosynthetic function. Increasing DHAR expression maintained higher levels of chlorophyll, RbcL, light-harvesting complex II, and photosynthetic functioning, resulting in delayed leaf aging. The effect of DHAR expression on leaf aging inversely correlated with the level of lipid peroxidation, indicating that DHAR functions to protect against ROS-mediated damage. These observations support the conclusion that through its Asc recycling function, DHAR affects the level of foliar ROS and photosynthetic activity during leaf development and as a consequence, influences the rate of plant growth and leaf aging.
Quantitative Profiling of Arabidopsis Polar Glycerolipids in Response to Phosphorus Starvation. Roles of Phospholipases Dζ1 and Dζ2 in Phosphatidylcholine Hydrolysis and Digalactosyldiacylglycerol Accumulation in Phosphorus-Starved Plants
Authors: Li Maoyin , Welti Ruth , Wang Xuemin 
Published: August 2006

Abstract
Phosphorus is an essential macronutrient that often limits plant growth and development. Under phosphorus-limited conditions, plants undergo substantial alterations in membrane lipid composition to cope with phosphorus deficiency. To characterize the changes in lipid species and to identify enzymes involved in plant response to phosphorus starvation, 140 molecular species of polar glycerolipids were quantitatively profiled in rosettes and roots of wild-type Arabidopsis (Arabidopsis thaliana) and phospholipase D knockout mutants pldζ1, pldζ2, and pldζ1pldζ2. In response to phosphorus starvation, the concentration of phospholipids was decreased and that of galactolipids was increased. Phospholipid lost in phosphorus-starved Arabidopsis rosettes was replaced by an equal amount of galactolipid. The concentration of phospholipid lost in roots was much greater than in rosettes. Disruption of both PLDζ1 and PLDζ2 function resulted in a smaller decrease in phosphatidylcholine and a smaller increase in digalactosyldiacylglycerol in phosphorus-starved roots. The results suggest that hydrolysis of phosphatidylcholine by PLDζs during phosphorus starvation contributes to the supply of inorganic phosphorus for cell metabolism and diacylglycerol moieties for galactolipid synthesis.
IMMUTANS Does Not Act as a Stress-Induced Safety Valve in the Protection of the Photosynthetic Apparatus of Arabidopsis during Steady-State Photosynthesis
Authors: Rosso Dominic , Ivanov Alexander G. , Fu Aigen , Geisler-Lee Jane , Hendrickson Luke , Geisler Matt , Stewart Gregory , Krol Marianna , Hurry Vaughan , Rodermel Steven R. , Maxwell Denis P. , Hüner Norman P.A. 
Published: August 2006

AbstractIMMUTANS (IM) encodes a thylakoid membrane protein that has been hypothesized to act as a terminal oxidase that couples the reduction of O2 to the oxidation of the plastoquinone (PQ) pool of the photosynthetic electron transport chain. Because IM shares sequence similarity to the stress-induced mitochondrial alternative oxidase (AOX), it has been suggested that the protein encoded by IM acts as a safety valve during the generation of excess photosynthetically generated electrons. We combined in vivo chlorophyll fluorescence quenching analyses with measurements of the redox state of P 700 to assess the capacity of IM to compete with photosystem I for intersystem electrons during steady-state photosynthesis in Arabidopsis (Arabidopsis thaliana). Comparisons were made between wild-type plants, im mutant plants, as well as transgenics in which IM protein levels had been overexpressed six (OE-6×) and 16 (OE-16×) times. Immunoblots indicated that IM abundance was the only major variant that we could detect between these genotypes. Overexpression of IM did not result in increased capacity to keep the PQ pool oxidized compared to either the wild type or im grown under control conditions (25°C and photosynthetic photon flux density of 150 μmol photons m−2 s−1). Similar results were observed either after 3-d cold stress at 5°C or after full-leaf expansion at 5°C and photosynthetic photon flux density of 150 μmol photons m−2 s−1. Furthermore, IM abundance did not enhance protection of either photosystem II or photosystem I from photoinhibition at either 25°C or 5°C. Our in vivo data indicate that modulation of IM expression and polypeptide accumulation does not alter the flux of intersystem electrons to P 700 + during steady-state photosynthesis and does not provide any significant photoprotection. In contrast to AOX1a, meta-analyses of published Arabidopsis microarray data indicated that IM expression exhibited minimal modulation in response to myriad abiotic stresses, which is consistent with our functional data. However, IM exhibited significant modulation in response to development in concert with changes in AOX1a expression. Thus, neither our functional analyses of the IM knockout and overexpression lines nor meta-analyses of gene expression support the model that IM acts as a safety valve to regulate the redox state of the PQ pool during stress and acclimation. Rather, IM appears to be strongly regulated by developmental stage of Arabidopsis.
Rice NTRC Is a High-Efficiency Redox System for Chloroplast Protection against Oxidative Damage
Authors: Pérez-Ruiz Juan Manuel , Spínola María Cristina , Kirchsteiger Kerstin , Moreno Javier , Sahrawy Mariam , Cejudo Francisco Javier 
Published: August 2006

AbstractOne of the mechanisms plants have developed for chloroplast protection against oxidative damage involves a 2-Cys peroxiredoxin, which has been proposed to be reduced by ferredoxin and plastid thioredoxins, Trx x and CDSP32, the FTR/Trx pathway. We show that rice (Oryza sativa) chloroplast NADPH THIOREDOXIN REDUCTASE (NTRC), with a thioredoxin domain, uses NADPH to reduce the chloroplast 2-Cys peroxiredoxin BAS1, which then reduces hydrogen peroxide. The presence of both NTR and Trx-like domains in a single polypeptide is absolutely required for the high catalytic efficiency of NTRC. An Arabidopsis thaliana knockout mutant for NTRC shows irregular mesophyll cell shape, abnormal chloroplast structure, and unbalanced BAS1 redox state, resulting in impaired photosynthesis rate under low light. Constitutive expression of wild-type NTRC in mutant transgenic lines rescued this phenotype. Moreover, prolonged darkness followed by light/dark incubation produced an increase in hydrogen peroxide and lipid peroxidation in leaves and accelerated senescence of NTRC-deficient plants. We propose that NTRC constitutes an alternative system for chloroplast protection against oxidative damage, using NADPH as the source of reducing power. Since no light-driven reduced ferredoxin is produced at night, the NTRC-BAS1 pathway may be a key detoxification system during darkness, with NADPH produced by the oxidative pentose phosphate pathway as the source of reducing power.
Functional Profiling Reveals That Only a Small Number of Phytochrome-Regulated Early-Response Genes inArabidopsisAre Necessary for Optimal Deetiolation
Authors: Khanna Rajnish , Shen Yu , Toledo-Ortiz Gabriela , Kikis Elise A. , Johannesson Henrik , Hwang Yong-Sic , Quail Peter H. 
Published: August 2006

AbstractIn previous time-resolved microarray-based expression profiling, we identified 32 genes encoding putative transcription factors, signaling components, and unknown proteins that are rapidly and robustly induced by phytochrome (phy)-mediated light signals. Postulating that they are the most likely to be direct targets of phy signaling and to function in the primary phy regulatory circuitry, we examined the impact of targeted mutations in these genes on the phy-induced seedling deetiolation process in Arabidopsis thaliana. Using light-imposed concomitant inhibition of hypocotyl and stimulation of cotyledon growth as diagnostic criteria for normal deetiolation, we identified three major mutant response categories. Seven (22%) lines displayed statistically significant, reciprocal, aberrant photoresponsiveness in the two organs, suggesting disruption of normal deetiolation; 13 (41%) lines displayed significant defects either unidirectionally in both organs or in hypocotyls only, suggesting global effects not directly related to photomorphogenic signaling; and 12 (37%) lines displayed no significant difference in photoresponsiveness from the wild type. Potential reasons for the high proportion of rapidly light-responsive genes apparently unnecessary for the deetiolation phenotype are discussed. One of the seven disrupted genes displaying a significant mutant phenotype, the basic helix-loop-helix factor–encoding PHYTOCHROME-INTERACTING FACTOR3-LIKE1 gene, was found to be necessary for rapid light-induced expression of the photomorphogenesis- and circadian-related PSEUDO-RESPONSE REGULATOR9 gene, indicating a regulatory function in the early phy-induced transcriptional network.
Marijuana use and depression among adults: testing for causal associations
Authors: Harder Valerie S. , Morral Andrew R. , Arkes Jeremy 
Published: August 2006

ABSTRACTAim  To determine whether marijuana use predicts later development of depression after accounting for differences between users and non‐users of marijuana.Design  An ongoing longitudinal survey of 12 686 men and women beginning in 1979.Setting  The National Longitudinal Survey of Youth of 1979, a nationally representative sample from the United States.Participants  A total of 8759 adults (age range 29–37 years) interviewed in 1994 had complete data on past‐year marijuana use and current depression.Measurements  Self‐reported past‐year marijuana use was tested as an independent predictor of later adult depression using the Center for Epidemiologic Studies—Depression questionnaire. Individual’s propensity to use marijuana was calculated using over 50 baseline covariates.Findings  Before adjusting for group differences, the odds of current depression among past‐year marijuana users is 1.4 times higher (95% CI: 1.1, 1.9) than the odds of depression among the non‐using comparison group. After adjustment, the odds of current depression among past‐year marijuana users is only 1.1 times higher than the comparison group (95% CI: 0.8, 1.7). Similarly, adjustment eliminates significant associations between marijuana use and depression in four additional analyses: heavy marijuana use as the risk factor, stratifying by either gender or age, and using a 4‐year lag‐time between marijuana use and depression.Conclusions  After adjusting for differences in baseline risk factors of marijuana use and depression, past‐year marijuana use does not significantly predict later development of depression. These findings are discussed in terms of their relevance for understanding possible causal effects of marijuana use on depression.
A randomized controlled pilot study of motivational interviewing for patients with psychotic and drug use disorders
Authors: Martino Steve , Carroll Kathleen M. , Nich Charla , Rounsaville Bruce J. 
Published: August 2006

ABSTRACTAims  This pilot study examined the efficacy of a two‐session motivational interview adapted for dually diagnosed psychotic and drug‐related disordered patients (DDMI) in comparison to a two‐session standard psychiatric interview (SI).Design  The study used a randomized controlled trial design. Participants received either DDMI or SI and were assessed at baseline, 4‐, 8‐ and 12‐week follow‐up points. The principal analysis for examination of treatment effects across time was a random effects regression model.Setting  Both DDMI and SI interviews served as pre‐admission intake interventions to an ambulatory specialty dual diagnosis intensive out‐patient and partial hospital program.Participants  Forty‐four treatment‐seeking participants (DDMI = 24; SI = 20) who had co‐occurring psychotic and drug‐related disorders were assigned randomly to the treatment conditions.Measurements  Primary outcomes were days of primary drug use, secondary drug use, alcohol use and psychotropic medication adherence, proportion of participants admitted into the program and days of attendance.Findings and conclusions  DDMI and SI resulted in improved treatment outcomes, but there were no main effects for the sample as a whole. Separate examination of primary cocaine and primary marijuana using subsamples, however, suggested that DDMI resulted in significantly better primary drug treatment outcomes for the cocaine‐using group, whereas SI resulted in significantly better primary drug treatment outcomes for the marijuana‐using group. These findings indicate that MI may not work equally well for all types of psychotic disordered dually diagnosed patients and that alternative approaches may be as effective in fostering improved substance use treatment outcomes for subgroups of these individuals.
Ablation of ovomucoid-induced allergic response by desensitization with recombinant ovomucoid third domain in a murine model
Authors: Rupa P , Mine Y 
Published: August 2006

SummaryAttempts to modulate the allergenic response by hypoallergens aimed at eliminating IgE-binding epitopes have been established recently for allergen immunotherapy. Desensitization offers an alternative approach to mounting a protective immune response. We have shown previously that mutation of the decisive amino acids in the B cell epitope of the ovomucoid third domain suppresses IgE binding reactivity against human patient sera and we hypothesize that this hypoallergenic variant could be a potential candidate molecule for specific immunotherapy against an ovomucoid-induced IgE reaction. The aim of this study was to investigate whether hyposensitization with the ovomucoid-modified isoform could desensitize ovomucoid-sensitized mice. We mapped the immunodominant B cell epitopes of ovomucoid in Balb/c mice. A hypoallergenic ovomucoid mutant isoform, having ablated allergenicity against patient sera, was used to desensitize ovomucoid-sensitized Balb/c mice by intraperitoneal injection. Female Balb/c mice were sensitized with intact ovomucoid molecule (Fovm) and desensitized with the modified isoform of the third domain of ovomucoid (GMFA). Intact ovomucoid-sensitized mice desensitized with phosphate-buffered saline (PBS) served as positive controls to maintain hypersensitivity. To gain insight into the efficacy of the modified ovomucoid variant in desensitization, effects on hypersensitivity reactions and histamine levels, followed by its association with antibody levels and cytokine profiles, were measured. Abrogation of the allergic response with complete suppression of anaphylactic symptoms and lower serum histamine levels was observed in the desensitized group by GMFA, accompanied by significantly reduced ovomucoid-specific IgE and IgG1 levels and enhanced specific IgG and IgG2a levels. The sensitized group showed severe anaphylactic symptoms, enhanced serum histamine concentrations and increased levels of specific IgE and IgG1. The level of interleukin (IL)-4 was decreased dramatically in the desensitized group and higher levels of interferon (IFN)-γ were found, whereas mice sensitized with intact ovomucoid exhibited significantly higher levels of IL-4 favouring a Th2 skewed pathway. We demonstrate clearly that GMFA is able to ablate ovomucoid-induced allergic reactions in sensitized mice. This occurs via a suppression of specific IgE accompanied by an increase in suppressor T cell activity. This approach offers some promise for the development of treatment against ovomucoid-induced allergic response.
Increased susceptibility of cord blood B lymphocytes to undergo spontaneous apoptosis
Authors: Kessel A , Yehudai D , Peri R , Pavlotzky E , Bamberger E , Tov N , Toubi E 
Published: August 2006

SummaryIn this study, we compared the rate of spontaneous apoptosis of B cells from umbilical cord blood with adult B cells and assessed the role of Bcl-2, CD5, interleukin (IL)-4 and B cell-activating factor in B cell spontaneous apoptosis. We found that spontaneous apoptosis of cultured B cells, as assessed by utilizing annexin-V binding, was significantly higher in cord blood than in healthy adult individuals (77·5; 95 CI, 73·5–81·5 versus 59·2; 95 CI, 54–64, respectively, P &lt; 0·0001) and further confirmed by 4′ 6-diamidino-2-phenylindole, dihydrochloride (DAPI) staining. Whereas the expression of B cell-activating factor from the tumour necrosis factor family (BAFF) receptor mRNA was similar in B cells from adults and cord blood, we detected lower levels of circulating BAFF in the serum of cord blood (0·68 ± 0·13 ng versus 1·83 ± 0·54 ng, P = 0·01). The latter may explain, in part, our observation of lower levels of mean fluorescence intensity of Bcl-2 in cord B cells compared with adults (1·6 ± 0·9 versus 2·85 ± 1·3, P = 0·033). CD19+ CD5+ B cells from cord blood underwent a lower rate of apoptosis in comparison to CD19+ CD5– B cells (25·1 ± 9·3%versus 58·5 ± 12·5%, P &lt; 0·0001). This pattern of sensitivity was comparable in adult blood (15 ± 5·5%versus 22·7 ± 9·3%, P = 0·01). Nevertheless, the rate of apoptosis was higher in CD19+ CD5+ from cord blood compared to CD19+ CD5+ from adults (25·1 ± 9·3%versus 15 ± 5·5%, P = 0·0013). The addition of rIL-4 (10 u/ml) to cultured cells decreased B cell apoptosis in a similar fashion in both cord and adults blood. This rescue was strengthened when BAFF (100 µg/ml) was further added. Thus, alterations in Bcl-2 or serum BAFF level may explain the increased rate of cord blood B cell apoptosis.
The role of CD4+CD25+ T cells in autoantibody production in murine lupus
Authors: Hsu W-T , Suen J-L , Chiang B-L 
Published: August 2006

SummarySystemic lupus erythematosus (SLE) is a chronic, systemic autoimmune disease characterized by the loss of tolerance to self-antigen. Because it is currently not known if regulatory T (Treg) cells are involved in the pathogenesis, we determined the frequency of CD4+CD25+ T cells and assayed the related gene expression levels in CD4+CD25+ T cells isolated from both lupus mice (NZB/NZW F1) and normal control mice (DBA2/NZW F1). The results showed that the frequency of CD4+CD25+ T cells in lupus mice was lower than that of normal mice. Except for the high expression level of interleukin (IL)-10 mRNA, CD4+CD25+ T cells from lupus mice expressed normal forkhead box P3 (Foxp3) and transforming growth factor (TGF)-β mRNA, and exerted suppressive functions. Furthermore, we depleted CD25+ Treg cells of non-autoimmune mice with anti-CD25 antibody and broke their tolerance with apoptotic cell-pulsed dendritic cells for the follow-up of autoantibody levels. The mice in the CD25+ cell-depleted group had higher titres of anti-double-strand/single-strand DNA antibodies than those of the isotype control antibody-treated group. These findings indicated that CD4+CD25+ T cells might be involved in the regulatory mechanism of autoantibody production.
Characterization of chicken epidermal dendritic cells
Authors: Igyártó Botond‐Zoltán , Lackó Erzsébet , Oláh Imre , Magyar Attila 
Published: August 2006

SummaryIt has been known for 15 years that the chicken epidermis contains ATPase+ and major histocompatibility complex class II‐positive (MHCII+) dendritic cells. These cells were designated as Langerhans cells but neither their detailed phenotype nor their function was further investigated. In the present paper we demonstrate a complete overlapping of ATPase, CD45 and vimentin staining in all dendritic cells of the chicken epidermis. The CD45+ ATPase+ vimentin+ dendritic cells could be divided into three subpopulations: an MHCII+ CD3– KUL01+ and 68.1+ (monocyte‐macrophage subpopulation markers) subpopulation, an MHCII– CD3– KUL01– and 68.1– subpopulation and an MHCII– CD3+ KUL01– and 68.1– subpopulation. The first population could be designated as chicken Langerhans cells. The last population represents CD4– CD8– T‐cell receptor‐αβ– and ‐γδ– natural killer cells with cytoplasmic CD3 positivity. The epidermal dendritic cells have a low proliferation rate as assessed by bromodeoxyuridine incorporation. Both in vivo and in vitro experiments showed that dendritic cells could be mobilized from the epidermis. Hapten treatment of epidermis resulted in the decrease of the frequency of epidermal dendritic cells and hapten‐loaded dendritic cells appeared in the dermis or in in vitro culture of isolated epidermis. Hapten‐positive cells were also found in the so‐called dermal lymphoid nodules. We suggest that these dermal nodules are responsible for some regional immunological functions similar to the mammalian lymph nodes.
Extravasation mucocele involving the ventral surface of the tongue (glands of Blandin–Nuhn)
Authors: GUIMARÃES M. S. , HEBLING J. , FILHO V. A. P. , SANTOS L. L. , VITA T. M. , COSTA C. A. S. 
Published: August 2006

Summary.  Background.  Mucocele is a lesion that involves the salivary glands and respective current ducts caused mainly by traumas in the affected area. Two different histological forms can be found: extravasation phenomenon and mucus‐retention cyst where the former is the most frequently observed involving minor salivary glands such as the glands present in the anterior portion of the ventral surface of the tongue (glands of Blandin–Nuhn).Case Report.  This report describes a large lesion involving the ventral surface of the tongue that was definitively diagnosed by histological examination as extravasation mucocele.Conclusion.  Important concepts are reviewed to help clinicians correctly diagnose and treat this pathology.