bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular characterization of the fish‐pathogenic fungus Aphanomyces invadans
Authors: Lilley J H , Hart D , Panyawachira V , Kanchanakhan S , Chinabut S , Söderhäll K , Cerenius L 
Published: May 2003

Abstract Aphanomyces invadans (Saprolegniaceae) is a peronosporomycete fungus associated with the serious fish disease, epizootic ulcerative syndrome (EUS), also known as mycotic granulomatosis. In this study, interspecific relationships were examined between A. invadans isolates and other aquatic animal pathogenic Saprolegniaceae, and saprophytic Saprolegniaceae from EUS‐affected areas. Restriction fragment length polymorphisms and sequences of ribosomal DNA confirmed that A. invadans is distinct from all other species studied. A sequence from the internal transcribed spacer region ITS1, unique to A. invadans, was used to design primers for a PCR‐based diagnostic test. Intraspecific relationships were also examined by random amplification of polymorphic DNA using 20 isolates of A. invadans from six countries. The isolates showed a high degree of genetic homogeneity using 14 random ten‐mer primers. This provides evidence that the fungus has spread across Asia in one relatively rapid episode, which is consistent with reports of outbreaks of EUS. Physiological distinctions between A. invadans and other Aphanomyces species based on a data set of 16 growth parameters showed remarkable taxonomic congruence with the molecular phylogeny.
Uptake of erythromycin by first‐feeding sockeye salmon, Oncorhynchus nerka (Walbaum), fed live or freeze‐dried enriched adult Artemia or medicated pellets
Authors: Cook M A , Rust M B , Massee K , Majack T , Peterson M E 
Published: May 2003

AbstractThe potential to use adult Artemia to deliver erythromycin to first‐feeding sockeye salmon, Oncorhynchus nerka (Walbaum), was investigated in three trials. In the first trial, first‐feeding sockeye were fed live erythromycin enriched adult Artemia or pellets containing equal amounts of erythromycin for 35 days. At the end of the trial, tissue erythromycin concentration of the fish fed the live Artemia was significantly greater (P < 0.05, 25.52 ± 1.29 μg mL−1; mean ± SEM), than the tissue concentration of the fish fed the pellets (0.72 ± 0.01 μg mL−1). In the second trial, first‐feeding sockeye were fed either live or freeze‐dried bioencapsulated erythromycin (adult Artemia) or pellets containing erythromycin daily for 21 days. Mean daily erythromycin concentration in fish fed the freeze‐dried Artemia, live Artemia, or pellets did not differ significantly. In the third trial, apparent erythromycin digestibility was determined. Significantly more (P < 0.05) erythromycin was retained by juvenile sockeye fed freeze‐dried bioencapsulated erythromycin (98.3 ± 1.0%) compared with medicated pellets (89.2 ± 1.7%). Uptake of bioencapsulated erythromycin from adult Artemia (live or freeze‐dried) appears to be greater than uptake from pellets. Freeze‐dried and live Artemia were equally effective at delivery suggesting enriched freeze‐dried adult Artemia could be produced into a highly palatable, consistent, off‐the‐shelf product.
Isolation of a highly pathogenic Vibrio pelagius strain associated with mass mortalities of turbot, Scophthalmus maximus (L.), larvae
Authors: Villamil L , Figueras A , Toranzo A E , Planas M , Novoa B 
Published: May 2003

AbstractA bacterial strain, characterized as Vibrio pelagius (Hq 222), was isolated from a turbot, Scophthalmus maximus (L.), larvae mass mortality in a commercial fish farm in Spain. Turbot larvae, post‐larvae (0.2 g) and juveniles (5 and 15 g) were experimentally infected. The bacterium appeared to be very virulent for larvae and post‐larvae, LD50 being <5 bacteria mL−1 for larvae 1 week post‐infection and 3.9 × 105 bacteria mL−1 in post‐larvae at day 12 post‐infection. The bacterial strain was recovered in pure culture from the internal organs of infected fish. Histological lesions in post‐larvae exhibited swelling and necrosis of gill secondary lamellae, sloughing of intestinal mucosa and necrosis of haematopoietic tissue in the kidney. Vibrio pelagius (Hq 222) was able to grow in sterile sea water when incubated at room temperature or at 15 °C. Vibrio pelagius (Hq 222) was more adherent to the turbot cell lines TV‐1 and TF than Escherichia coli. In both cell lines, the number of adhered bacteria increased with incubation time.
Protective effect of cutaneous antibody produced by channel catfish, Ictalurus punctatus (Rafinesque), immune to Ichthyophthirius multifiliis Fouquet on cohabited non‐immune catfish
Authors: Xu D‐H , Klesius P H 
Published: May 2003

AbstractFish which survive a sublethal ichthyophthiriasis acquire protective immunity against Ichthyophthirius multifiliis Fouquet (Ich). This study evaluated the protective effect of cutaneous antibody secreted by channel catfish, Ictalurus punctatus (Rafinesque), immune to Ich on cohabited non‐immune catfish. Non‐immune and immune fish controls were separately maintained and infected with theronts. The Ich infection was assessed by scoring 0, <50, 50–100, and >100 trophonts fish−1 at 5 days post‐infection. The results of infection showed that cohabited fish at the ratio of 15 non‐immune to two immune fish had <50 trophonts fish−1. Eighty per cent of the cohabited fish at the ratio of 10 non‐immune to two immune fish showed 0 or <50 trophonts fish−1. The 76% of control non‐immune fish had more than 100 trophonts fish−1. The control immune fish had 0 trophonts fish−1. Anti‐Ich antibody was detected using enzyme‐linked immunosorbent assay in water samples taken from tanks containing immune fish after the water samples were concentrated 40‐fold. The study suggests that immune fish cohabited with non‐immune fish may protect non‐immune fish against Ich infection.
A transformation vector for the production of marker‐free transgenic plants containing a single copy transgene at high frequency
Authors: Sugita Koichi , Kasahara Takehide , Matsunaga Etsuko , Ebinuma Hiroyasu 
Published: May 2003

SummaryWe represent here the GST‐MAT vector system. The R recombinase gene of the site‐specific recombination system R/RS from Zygosaccharomyces rouxii was fused to the chemical inducible promoter of the glutathione‐S‐transferase (GST‐II‐27) gene from Zea mays. Upon excision, the isopentenyltransferase (ipt) gene that is used as a selectable marker gene is removed. When the cauliflower mosaic virus 35S promoter (CaMV 35S) was used to express R recombinase, 67% of the marker‐free transgenic plants had more than three transgene copies. Because the CaMV 35S promoter transiently and efficiently excised the ipt gene before callus and adventitious bud formation, the frequency of emergence of the ipt‐shooty explants with a single T‐DNA copy might be reduced. In this study we show that the GST‐MAT vector efficiently produced transgenic ipt‐shooty explants from 37 (88%) out of 42 differentiated adventitious buds and marker‐free transgenic plants containing the GUS gene from five (14%) out of 37 ipt‐shooty lines. Furthermore, the GST‐MAT vector also induced two marker‐free transgenic plants without the production of ipt‐shooty intermediates. Southern blot analysis showed that six (86%) out of seven marker‐free transgenic plants had a single GUS gene. This result suggests that the GST‐MAT vector is useful to generate high frequency, marker‐free transgenic plants containing a single transgene.
Modulation by phytochrome of the blue light‐induced extracellular acidification by leaf epidermal cells of pea (Pisum sativum L.): a kinetic analysis
Authors: Elzenga J. Theo M. , Staal Marten , Prins Hidde B. A. 
Published: May 2003

SummaryBlue light induces extracellular acidification, a prerequisite of cell expansion, in epidermis cells of young pea leaves, by stimulation of the proton pumping‐ATPase activity in the plasma membrane. A transient acidification, reaching a maximum 2.5–5 min after the start of the pulse, could be induced by pulses as short as 30 msec. A pulse of more than 3000 μmol m−2 saturated this response. Responsiveness to a second light pulse was recovered with a time constant of about 7 min. The fluence rate‐dependent lag time and sigmoidal increase of the acidification suggested the involvement of several reactions between light perception and activation of the ATPase. In wild‐type pea plants, the fluence response relation for short light pulses was biphasic, with a component that saturates at low fluence and one that saturates at high fluence. The phytochrome‐deficient mutant pcd2 showed a selective loss of the high‐fluence component, suggesting that the high‐fluence component is phytochrome‐dependent and the low‐fluence component is phytochrome‐independent. Treatment with the calmodulin inhibitor W7 also led to the elimination of the phytochrome‐dependent high‐fluence component. Simple models adapted from the one used to simulate blue light‐induced guard cell opening failed to explain one or more elements of the experimental data. The hypothesis that phytochrome and a blue light receptor interact in a short‐term photoresponse is endorsed by model calculations based upon a three‐step signal transduction cascade, of which one component can be modulated by phytochrome.
Transformation of Arabidopsis with the codA gene for choline oxidase enhances freezing tolerance of plants
Authors: Sakamoto Atsushi , Valverde Roberto , Alia  , Chen Tony H. H. , Murata Norio 
Published: May 2003

Summary Arabidopsis thaliana was transformed with the codA gene from Arthrobacter globiformis, which encodes choline oxidase, the enzyme that synthesizes glycinebetaine from choline. The transformation enabled the plants to accumulate glycinebetaine in chloroplasts, and significantly enhanced the freezing tolerance of plants. Furthermore, the photosynthetic machinery of transformed plants was more tolerant to freezing stress than that of wild‐type plants. Exogenous application of glycinebetaine also increased the freezing tolerance of wild‐type plants, suggesting that the presence of glycinebetaine in transformed plants had enhanced their ability to tolerate freezing stress. Northern blotting analysis revealed that the enhancement of freezing tolerance was not related to the expression of four cold‐regulated genes. These results suggest that engineering of the biosynthesis of glycinebetaine by transformation with the codA gene might be an effective method for enhancing the freezing tolerance of plants.
Expression of Brassica juncea 3‐hydroxy‐3‐methylglutaryl CoA synthase is developmentally regulated and stress‐responsive
Authors: Alex Deepa , Bach Thomas J. , Chye Mee‐Len 
Published: May 2003

Summary3‐Hydroxy‐3‐methylglutaryl‐coenzyme A synthase (HMGS) is an enzyme in mevalonate biosynthesis. In plants, investigations have focused on HMG CoA reductase (HMGR) and less is known of the preceding enzyme, HMGS. To understand the regulation of HMGS, we have isolated a Brassica juncea cDNA encoding HMGS, BjHMGS1, for use as a hybridization probe in Northern blot analyses. BjHMGS is expressed in all plant organs and shows developmental regulation in flower, seed and seedling, with highest expression in early development. In seedlings, expression is highest in young hypocotyls and is induced during the greening of etiolated cotyledons. BjHMGS is down‐regulated by abscisic acid, osmotic stress and dehydration, the effects of which arrested seedling growth. Thus BjHMGS expression shows correlation with rapid cell division and growth, like HMGR. This is not unexpected, as mevalonate is the precursor to many essential isoprenoid compounds, including sterols for membrane biogenesis. Wounding, methyl jasmonate or salicylic acid induce BjHMGS expression, suggesting that, like HMGR, HMGS is involved in defence. As in animals, coordinated regulation of HMGS with HMGR occurred in B. juncea upon germination and in response to salicylic acid. HMGS assays confirmed that Escherichia coli‐expressed recombinant BjHMGS1 shows HMGS activity that is inhibited by F244, a specific inhibitor of HMGS. Southern blot analysis revealed gene families encoding HMGS in Brassica species and a summation of homologous genes in the fusion amphidiploid genome of B. juncea, a bi‐parental species derived from diploids B. nigra and B. campestris.
The TATA motif, the CAA motif and the poly(T) transcription termination motif are all important for transcription re‐initiation on plant tRNA genes
Authors: Yukawa Yasushi , Sugita Mamoru , Choisne Nathalie , Small Ian , Sugiura Masahiro 
Published: May 2003

SummaryThe effect of alteration of 5′ and 3′ flanking sequences on the transcription of plant tRNA genes was analysed using an RNA polymerase III‐dependent in vitro transcription system derived from nuclei of cultured tobacco cells. A TATA‐like sequence and the CAA motif frequently observed upstream of plant tRNA genes, and the poly(T) stretch usually present downstream, were shown to be necessary for efficient re‐initiation of transcription. The CAA motif was shown to be a transcription initiation site. Introduction of the CAA and TATA‐like motifs into a gene naturally lacking them greatly enhanced transcription by promoting efficient re‐initiation.
Phytochromes confer the photoperiodic control of flowering in rice (a short‐day plant)
Authors: Izawa Takeshi , Oikawa Tetsuo , Tokutomi Satoru , Okuno Kazutoshi , Shimamoto Ko 
Published: May 2003

SummaryThe photoperiodic sensitivity 5 (se5) mutant of rice, a short‐day plant, has a very early flowering phenotype and is completely deficient in photoperiodic response. We have cloned the SE5 gene by candidate cloning and demonstrated that it encodes a putative heme oxygenase. Lack of responses of coleoptile elongation by light pulses and photoreversible phytochromes in crude extracts of se5 indicate that SE5 may function in phytochrome chromophore biosynthesis. Ectopic expression of SE5 cDNA by the CaMV 35S promoter restored the photoperiodic response in the se5 mutant. Our results indicate that phytochromes confer the photoperiodic control of flowering in rice. Comparison of se5 with hy1, a counterpart mutant of Arabidopsis, suggests distinct roles of phytochromes in the photoperiodic control of flowering in these two species.
Epistatic repression of PHANTASTICA and class 1 KNOTTED genes is uncoupled in tomato
Authors: Koltai Hinanit , Bird David McKenzie 
Published: May 2003

SummaryClass 1 KNOTTED genes (KNOX) and PHANTASTICA (PHAN) are both central to meristem establishment and maintenance and, in maize and Antirrhinum, it has been proposed that PHAN acts as an epigenetic repressor of KNOX. In tomato, a distinct spatial distribution of Tkn2 KNOX transcripts compared to Antirrhinum and maize suggests either a different spatial distribution of tomato PHAN (Le‐phan) transcripts, or that PHAN alone is insufficient for KNOX repression in tomato. We established the pattern of Le‐phan expression, including a first demonstration of PHAN expression in healthy roots, and found Le‐phan and Tkn2 transcripts to be temporally and spatially coincidental, with PHAN exhibiting an expression pattern in tomato distinct from that in plants with simple leaves. Our results imply that the expression of Le‐phan is insufficient for the repression of Tkn2 in tomato and suggest an expanded role for either gene in the establishment of cell identity in plant development.
Expression patterns of genes encoding HD‐ZipIV homeo domain proteins define specific domains in maize embryos and meristems
Authors: Ingram Gwyneth C. , Boisnard‐Lorig Corinne , Dumas Christian , Rogowsky Peter M. 
Published: May 2003

SummaryA family of homeo box genes with cell layer‐specific expression patterns defining subdomains of the embryo and certain meristems has been isolated from maize. These genes encode proteins from the class of plant specific homeo domain‐leucine zipper (HD‐Zip) transcription factors containing the previously described ZmOCL1 protein, and have been designated ZmOCL2, ZmOCL3, ZmOCL4 and ZmOCL5. ZmOCL3, ZmOCL4 and ZmOCL5, like ZmOCL1, showed essentially L1 or epidermis‐specific expression. However, each gene was expressed in a distinct region of the embryonic protoderm during early development, with ZmOCL3 showing suspensor‐specific expression, ZmOCL4 transcripts being localized to the adaxial face of the embryo proper and ZmOCL5 showing a more abaxial expression pattern. All three genes were also expressed in vegetative, inflorescence and floral apices, although ZmOCL3 transcripts were excluded from meristems and very young organ primordia. In contrast, ZmOCL2 expression was entirely meristem‐specific and was excluded from the L1 layer, appearing instead to be largely restricted to a cell layer directly beneath the L1, especially in floral meristems. This expression pattern is unprecedented and may indicate that cell‐layer organization in maize meristems is more complex than that suggested by the classical L1/L2 (outer cell layer/inner cell mass) model. These differing expression patterns indicate that the members of the HD‐ZipIV family of maize may not only play roles in defining different regions of the epidermis during embryonic development, but could also be responsible for maintaining cell‐layer identity in meristematic regions.
Fusion genetic analysis of gibberellin signaling mutants
Authors: Raventos Dora , Meier Carsten , Jensen Ole Mattsson anders B. , Mundy John 
Published: May 2003

SummaryA fusion genetic strategy was used to identify gibberellin (GA) signaling mutants in transgenic Arabidopsis expressing the β‐glucuronidase (GUS) and firefly luciferase (LUC) reporter genes under control of the GA‐responsive GASA1 promoter. Initial analyses determined the spatial and temporal patterns of reporter expression, and showed that reporter induction by GA was antagonized by ABA. γ‐Irradiated M2 progeny with altered reporter activities were identified by LUC bioimaging followed by GUS assays and northern hybridization of the endogenous GASA1 mRNA. Genetic analysis showed that three mutants, which overexpressed both reporters and endogenous GASA1, were caused by recessive (goe1 and goe2, for GASA over‐expressed) and semi‐dominant (goe3) mutations at different loci. These mutants are altered in their sensitivity to GA and the GA biosynthetic inhibitor paclobutrazol, and in the expression of several GA signaling related genes.
A survey of the decision‐making needs of Canadians faced with complex health decisions
Authors: O'Connor Annette M. , Drake Elizabeth R. , Wells George A. , Tugwell Peter , Laupacis Andreas , Elmslie Tom 
Published: May 2003

AbstractObjective To describe the decision‐making needs of Canadians when faced with ‘complex’ health decisions characterized by balancing advantages against disadvantages. Although a national report emphasized that public confidence in the health‐care system depends on support for personal knowledge and decision‐making, there has been no systematic investigation of the Canadian population's decision‐making needs.Design Cross‐sectional telephone survey using random digit dialling.Participants National sample of 635 adults over 18 years of age, living in Canada.Results Forty‐two percentage of eligible contacts participated. Sixty‐five percent of contacts reported making ‘complex’ health decisions, commonly about medical or surgical treatments or birth control, and more commonly by women and by married/separated individuals. Most respondents took an active role in their decisions, often sharing the process with their partner or family. Being younger was associated with a more independent role. Physicians were more often involved in the decisions of respondents with less education. Fifty‐nine percent of respondents experienced decisional conflict; more conflict was seen with those who were female and feeling uninformed about options, pressured to select one particular option, and unready or unskilled in decision‐making. Less decisional conflict was seen in those who reported birth control decisions and in those who were 70 years and older. Participants used several strategies when deliberating about choices including: information gathering, clarifying their values, and seeking support and information from others. Personal counselling and printed information materials were commonly preferred methods of learning about options. ‘Essential’ criteria for judging satisfactory decision‐making included: having sufficient knowledge about the options, outcomes, and probabilities; being clear about values; selecting and implementing a choice that agrees with personal values; and expressing satisfaction with the choice.Conclusions Canadians, particularly women, face difficult decisions and need support and information from credible sources.
What factors are associated with a woman's decision to take hormone replacement therapy? Evaluated in the context of a decision aid
Authors: Clark Heather D. , O'Connor Annette M. , Graham Ian D. , Wells George A. 
Published: May 2003

AbstractObjectives  To understand the factors associated with a post‐menopausal woman deciding to take hormone replacement therapy (HRT) after reviewing a decision aid (DA) and having a counselling visit with her physician as well as the factors associated with the act of taking HRT 2 months after the counselling interview.Design  A secondary analysis of data collected for a randomized controlled trial evaluating two DAs.Main outcome results  Although 28% of women were uncertain regarding their decision after the counselling interview, only 2.4% of women, at the assessment at 2 months, had not made a decision. The most significant factor associated with the decision to take HRT, after the physician visit, was the physician preference (OR: 62, 95% CI: 13.3, 289.7). Physician preference (OR: 78, 95% CI: 6.2, 975) remained the most significant factor for taking HRT 2 months after the counselling interview followed by low uncertainty about the decision (OR: 0.4, 95% CI: 0.2, 0.7).Conclusion  Physician preference was the factor that was most associated with the woman's decision following counselling and 2 months later. Qualitative evaluation of the interview process involving the patient and physician would determine whether the patient and physician are reaching a shared decision or is the physician preference influencing the patient.
Patient participation in decision‐making on the introduction of home respiratory care: who does not participate?
Authors: Hämäläinen Päivi M. , Perälä Marja‐Leena , Poussa Tuija , Pelkonen Marjaana 
Published: May 2003

AbstractObjectives  In this study we examined home respiratory patients' participation in decision‐making on whether to begin home respiratory care therapy, and this participation in decision‐making during the latest visit to the clinic.Subjects and methods  The target population consisted of patients who were using home respiratory care devices and who were visiting the outpatient clinics. Postal questionnaires were sent to 4159 patients (40% of respiratory care device users in Finland). A total of 3336 answered (response rate 80%) and 3153 were eligible for analysis. Odds ratios, chi‐square tests, Mann–Whitney U‐test and stepwise logistic regression analysis were used in the data analyses.Results  Patients who did not participate in decision‐making were more frequently older people, women and had lower income than the other patients. While these results parallel those of previous studies, in contrast we found more women with high education to be non‐participants. Non‐participants were not participating in decision‐making during their latest visit to the clinic in spite of the fact that they considered participation almost as important as did the other patients. Non‐participants were less satisfied with the quality of care given and felt that their life had improved less than did the other patients.Conclusion  The ethical principle of equal opportunities to participate in care decisions was not applied among home respiratory care patients in this study. The results challenge health‐care professionals to notice inequalities and improve their practices. The results can be generalized to all home respiratory care patients in Finland.