bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Arabidopsis hrl1 mutation reveals novel overlapping roles for salicylic acid, jasmonic acid and ethylene signalling in cell death and defence against pathogens
Authors: Devadas Sendil K. , Enyedi Alexander , Raina Ramesh 
Published: March 2003

SummaryDefence against pathogens in Arabidopsis is orchestrated by at least three signalling molecules: salicylic acid (SA), jasmonic acid (JA) and ethylene (ET). The hrl1 (hypersensitive response‐like lesions 1) mutant of Arabidopsis is characterized by spontaneous necrotic lesions, accumulation of reactive oxygen species, constitutive expression of SA‐ and ET/JA‐responsive defence genes, and enhanced resistance to virulent bacterial and oomycete pathogens. Epistasis analyses of hrl1 with npr1, etr1, coi1 and SA‐depleted nahG plants revealed novel interactions between SA and ET/JA signalling pathways in regulating defence gene expression and cell death. RNA gel‐blot analysis of RNA isolated separately from the lesion+ and the lesion– leaves of double mutants of hrl1 revealed different signalling requirements for the expression of defence genes in these tissues. Expression of the ET/JA‐responsive PDF1.2 gene was markedly reduced in hrl1 npr1 and in SA‐depleted hrl1 nahG plants. In hrl1 nahG plants, expression of PDF1.2 was regulated by benzathiadiazole in a concentration‐dependent manner: induced at low concentration and suppressed at high concentration. The hrl1 etr1 plants lacked systemic PR‐1 expression, and exhibited compromised resistance to virulent Pseudomonas syringae and Peronospora parasitica. Inhibiting JA responses in hrl1 coi1 plants lead to exaggerated cell death and severe stunting of plants. Finally, the hrl1 mutation lead to elevated expression of AtrbohD, which encodes a major subunit of the NADPH oxidase complex. Our results indicate that defence gene expression and resistance against pathogens in hrl1 is regulated synergistically by SA and ET/JA defence pathways.
Downregulation of a chloroplast‐targeted β‐amylase leads to a starch‐excess phenotype in leaves
Authors: Scheidig Andreas , Fröhlich Anja , Schulze Silke , Lloyd James R. , Kossmann Jens 
Published: March 2003

SummaryA functional screen in Escherichia coli was established to identify potato genes coding for proteins involved in transitory starch degradation. One clone isolated had a sequence very similar to a recently described chloroplast‐targeted β‐amylase of Arabidopsis. Expression of the gene in E. coli showed that the protein product was a functional β‐amylase that could degrade both starch granules and solubilized amylopectin, while import experiments demonstrated that the β‐amylase was imported and processed into pea chloroplasts. To study the function of the protein in transitory starch degradation, transgenic potato plants were generated where its activity was reduced using antisense techniques. Analysis of plants reduced in the presence of this β‐amylase isoform showed that their leaves had a starch‐excess phenotype, indicating a defect in starch degradation. In addition, it was shown that the antisense plants degraded only 8–30% of their total starch, in comparison with 50% in the wild type, over the dark period. This is the first time that a physiological role for a β‐amylase in plants has been demonstrated.
Plant RanGAPs are localized at the nuclear envelope in interphase and associated with microtubules in mitotic cells
Authors: Pay Aniko , Resch Katja , Frohnmeyer Hanns , Fejes Erzsebet , Nagy Ferenc , Nick Peter 
Published: March 2003

SummaryIn animals and yeast, the small GTP‐binding protein Ran has multiple functions – it is involved in mediating (i) the directional passage of proteins and RNA through the nuclear pores in interphase cells; and (ii) the formation of spindle asters, the polymerization of microtubules, and the re‐assembly of the nuclear envelope in mitotic cells. Nucleotide binding of Ran is modulated by a series of accessory proteins. For instance, the hydrolysis of RanGTP requires stimulation by the RanGTPase protein RanGAP. Here we report the complementation of the yeast RanGAP mutant rna1 with Medicago sativa and Arabidopsis thaliana cDNAs encoding RanGAP‐like proteins. Confocal laser microscopy of Arabidopsis plants overexpressing chimeric constructs of GFP with AtRanGAP1 and 2 demonstrated that the fusion protein is localized to patchy areas at the nuclear envelope of interphase cells. In contrast, the cellular distribution of RanGAPs in synchronized tobacco cells undergoing mitosis is characteristically different. Double‐immunofluorescence shows that RanGAPs are co‐localized with spindle microtubules during anaphase, with the microtubular phragmoplast and the surface of the daughter nuclei during telophase. Co‐assembly of RanGAPs with tubulin correlates with these in vivo observations. The detected localization pattern is consistent with the postulated function of plant RanGAPs in the regulation of nuclear transport during interphase, and suggests a role for these proteins in the organization of the microtubular mitotic structures.
The plant disease resistance gene Asc‐1 prevents disruption of sphingolipid metabolism during AAL‐toxin‐induced programmed cell death
Authors: Spassieva Stefka D. , Markham Jonathan E. , Hille Jacques 
Published: March 2003

SummaryThe nectrotrophic fungus Alternaria alternata f.sp. lycopersici infects tomato plants of the genotype asc/asc by utilizing a host‐selective toxin, AAL‐toxin, that kills the host cells by inducing programmed cell death. Asc‐1 is homologous to genes found in most eukaryotes from yeast to humans, suggesting a conserved function. A yeast strain with deletions in the homologous genes LAG1 and LAC1 was functionally complemented by Asc‐1, indicating that Asc‐1 functions in an analogous manner to the yeast homologues. Examination of the yeast sphingolipids, which are almost absent in the lag1Δlac1Δ mutant, showed that Asc‐1 was able to restore the synthesis of sphingolipids. We therefore examined the biosynthesis of sphingolipids in tomato by labeling leaf discs with l‐[3‐3H]serine. In the absence of AAL‐toxin, there was no detectable difference in sphingolipid labeling between leaf discs from Asc/Asc or asc/asc leaves. In the presence of pathologically significant concentrations of AAL‐toxin however, asc/asc leaf discs showed severely reduced labeling of sphingolipids and increased label in dihydrosphingosine (DHS) and 3‐ketodihydrosphingosine (3‐KDHS). Leaf discs from Asc/Asc leaves responded to AAL‐toxin treatment by incorporating label into different sphingolipid species. The effects of AAL‐toxin on asc/asc leaflets could be partially blocked by the simultaneous application of AAL‐toxin and myriocin. Leaf discs simultaneously treated with AAL‐toxin and myriocin showed no incorporation of label into sphingolipids or long‐chain bases as expected. These results indicate that the presence of Asc‐1 is able to relieve an AAL‐toxin‐induced block on sphingolipid synthesis that would otherwise lead to programmed cell death.
SVISS – a novel transient gene silencing system for gene function discovery and validation in tobacco plants
Authors: Gosselé Véronique , Faché Ina , Meulewaeter Frank , Cornelissen Marc , Metzlaff Michael 
Published: March 2003

SummaryWe developed a novel, two‐component transient gene silencing system in which the satellite tobacco mosaic virus (STMV) is used as vector for the delivery of inhibitory RNA into tobacco plants and the tobacco mosaic virus strain U2 (TMV‐U2) is used as helper virus for supplying replication and movement proteins in trans. The main advantage of the system is that by uncoupling virus replication components from silencing induction components, the intensity of silencing becomes more pronounced. We call this system satellite virus‐induced silencing system (SVISS) and will demonstrate here its robustness, speed and effectiveness. We were able to obtain pronounced and severe knockout phenotypes for a range of targeted endogenous genes belonging to various biochemical pathways and expressed in different plant tissues, such as genes involved in leaf and flower pigmentation, genes for cell wall synthesis in leaf, stem and root tissues or a ubiquitous RNA polymerase gene. By tandem insertion of more than one target gene sequence into the vector, we were able to induce simultaneous knockouts of an endogenous gene and a transgene. SVISS is the first transient gene silencing system for Nicotiana tabacum, which is a genetically well‐characterized bridging species for the Solanaceae plant family.
Selection by phage display of a variant mustard trypsin inhibitor toxic against aphids
Authors: Ceci Luigi R. , Volpicella Mariateresa , Rahbé Yvan , Gallerani Raffaele , Beekwilder Jules , Jongsma Maarten A. 
Published: March 2003

SummaryThe mustard trypsin inhibitor, MTI‐2, is a potent inhibitor of trypsin with no activity towards chymotrypsin. MTI‐2 is toxic for lepidopteran insects, but has low activity against aphids. In an attempt to improve the activity of the inhibitor towards aphids, a library of inhibitor variants was constructed and cloned into the pRlac3 phagemid vector. The library of 9.3 × 107 independent colonies was created by randomisation of a stretch of five consecutive codons in the reactive site. Repeated selection rounds against bovine trypsin and chymotrypsin allowed the identification of novel, MTI‐2 derived, antitrypsin and antichymotrypsin inhibitors. Chy8, the selected variant with highest affinity for bovine chymotrypsin (Ki = 32 nm versus >1000 nm for the wild‐type) represents the strongest known recombinant chymotrypsin inhibitor of the MTI‐2 family. It is highly toxic to nymphs of the aphid Acyrthosiphon pisum, and moderately toxic to nymphs of Aphis gossypii and Myzus persicae. The LC50 of 73 µg ml−1 towards A. pisum is the lowest value known among chymotrypsin inhibitors. The aphicidal activity of Chy8 was improved eightfold compared to the wild‐type inhibitor. This demonstrates, for the first time, that bovine chymotrypsin provides a useful template to select engineered proteins highly toxic against these aphids. The selected gene will allow the development of transgenic crops that are protected against sucking insect pests.
A randomized clinical trial comparing intravenous immunoglobulin with high‐dose intravenous methylprednisolone, with or without subsequent oral prednisone administration, in adults with previously untreated severe autoimmune thrombocytopenic purpura
Authors: Godeau B. B. , Chevret S. , Varet B. , Zini J. M. , Bassompierre F. , Bierling P. 
Published: March 2003

To compare the response to intravenous immunoglobulin (IVIg) with the response to high‐dose methylprednisolone (HDMP) in previously untreated adults with severe AITP and to determine if oral prednisone (PRDN) is required after IVIg or HDMP infusions.M ethods 116 adults, previously untreated, with platelet count ≤ 20 × 109/L were assigned by simultaneous double randomization to receive either IVIg (0·7 g/kg body weight per day) or HDMP (15 mg/kg body weight per day, total daily dose less than 1 g) from day 1 to day 3 (randomization A), and then to receive either PRDN, 1 mg/kg body weight per day, or a placebo (randomization B), from day 4 to day 21 in blinded manner.R esults Between day 1 and day 21, the number of days on which platelet counts were above 50 × 109/L and above 20 × 109/L was significantly higher among the 56 patients receiving IVIg than among the 60 patients receiving HDMP (P = 0·008 and P = 0·013, respectively), and the percentage of patients who had a platelet count exceeding 50 × 109/L on day 5 was also higher in the IVIg group. During the second treatment period, PRDN was more effective than the placebo on all short‐term end points. Patients who received IVIg followed by PRDN had a significantly larger number of days with platelet counts > 50 × 109/L and > 20 × 109/L between day 1 and day 21 (P = 0·008 and P = 0·005, respectively) than patients treated with HDMP followed by PRDN. As regards the long‐term response, the percentage of remitters was 40% overall and was not influenced by the treatment allocation in either randomization period (A or B).C onclusion IVIg followed by PRDN appears to be the more effective treatment in adults with severe AITP.
Perceptions and motivations of Canadian autologous blood donors
Authors: Moltzan C. , Proulx N. , Bormanis J. , Lander N. , DeGroot H. , Rock G. 
Published: March 2003

. Preoperative autologous blood donation in Canada has increased in the last decade due to concerns about allogeneic blood safety. As economic policies necessitate the validation of autologous blood donation, it is important to assess potential changes. This study examines the motivations and perceptions of patients participating in a Canadian autologous blood donation programme.The study was conducted at the Ottawa Hospital, Civic Campus. Questionnaires were developed and then administered to 100 consecutive adult autologous blood donors. The questionnaires assessed patient demographics, motivation for participation and perceptions about blood safety.Autologous donation was presented to 82% of patients as an option by their physicians. However, 59% of all patients felt that they were motivated to donate by their own fears. Patients (87%) also felt that directed blood donation should be offered due to their perception that directed donation is safer. Three‐quarters of patients would be willing to pay for autologous donation.Patients are concerned about the safety of allogeneic blood and they are motivated to seek other alternatives despite the fact that allogeneic blood is very safe. These perceptions and motivations must be taken into account as health care policy changes are considered.
A prospective study of blood transfusion history and liver cancer in a high‐endemic area of Japan
Authors: Fujino Y. , Mizoue T. , Tokui N. , Yoshimura T. 
Published: March 2003

SummaryBackground: The high prevalence of liver cancer in Japan may be owing to infection with hepatitis C virus (HCV), for which the major transmission route is blood transfusion. However, among the general population, there have been few follow‐up studies of people with a history of transfusion. The purpose of this study was to examine whether such a history correlates with the development of liver cancer among the general population of this high‐endemic area.Study design and methods: The baseline survey was conducted between 1986 and 1991 among the population (15 597 people, aged 30–79) of Fukuoka prefecture, Japan. The participants were assessed for their transfusion history and other covariates using a baseline questionnaire. The relative risk (RR) of blood transfusion for liver cancer was estimated using the Cox proportional hazard model.Results: The RRs of transfusion for subsequent liver cancer were 1·86 (95% confidence interval (CI) = 1·05–3·29) in men and 4·20 (95% CI = 1·83–9·61) in women, after adjusting for covariates. Transfusion was associated with an increased risk of liver cancer, mainly in the group without hepatitis and cirrhosis (RR = 1·81, 95% CI = 0·84–3·91 – men; RR = 4·39, 95% CI = 1·37–14·02 – women).Conclusion: A history of blood transfusion carried a significant risk of developing liver cancer in the study region. The people with a history of transfusion should be monitored more aggressively for viral infections and liver disease, as they may not report the infection or they may be unaware that they are infected.
Morbidity assessment in urinary schistosomiasis infection through ultrasonography and measurement of eosinophil cationic protein (ECP) in urine
Authors: Leutscher Peter D. C. , Reimert Claus M. , Vennervald Birgitte J. , Ravaoalimalala Voahangy E. , Ramarokoto Charles E. , Serieye Jean , Raobelison Ando , Rasendramino Mamy , Christensen Niels O. , Esterre Philippe 
Published: March 2003

Summary In a Schistosoma haematobium‐endemic village in western Madagascar we evaluated ultrasonography and Eosinophil Cationic Protein (ECP) in urine as means to detect the associated urinary tract pathology. 192 individuals were matched according to age and sex, and grouped into infected persons with bladder and, if present, kidney pathology (n= 96); infected persons without pathology (n= 48) and noninfected persons without pathology (n= 48). The median urinary egg count was significantly higher in individuals with ultrasonographically detectable urinary tract pathology (115 eggs/10 ml urine) than in infected persons without (45 eggs/10 ml of urine). At 136 ng/ml, the median ECP level was significantly higher in the 144 infected individuals than in the 48 noninfected persons (0.35 ng/ml). Egg excretion correlated positively with ECP level. The median ECP level was significantly higher in the group with ultrasonographically detectable urinary tract pathology than in the group without (183 ng/ml vs. 67 ng/ml). The results suggest that minor degrees of pathology, particularly at an early stage of infection with S. haematobium, might be overlooked by ultrasonography despite the presence of marked inflammation, as indicated by markedly increased urinary ECP levels in infected individuals without ultrasonographically detectable urinary tract pathology. ECP may therefore provide important information on the evolution of S. haematobium‐associated urinary tract morbidity.
Genotypic patterns of multiple isolates of M. tuberculosis from tuberculous HIV patients
Authors: Lourenço M. C. S. , Grinsztejn B. , Fandinho‐Montes F. C. O. , da Silva M. G. , Saad M. H. F. , Fonseca L. S. 
Published: March 2003

Summary We investigated whether the recurrence of tuberculosis in HIV‐infected patients is due to an exogenous reinfection or relapses after antituberculosis chemotherapy. We reviewed clinical information on 32 patients at a Rio de Janeiro hospital from whom multiple Mycobacterium tuberculosis isolates were taken. All isolates were analysed by DRE‐PCR fingerprinting technique, and those with identical DRE‐PCR patterns were analysed by the RFLP method. Twenty patients had M. tuberculosis simultaneously isolated from different organs. These patients and nine others with sequential positive cultures after 2 months of therapy showed stable DRE‐PCR and RFLP patterns. One patient's isolate became resistant to isoniazid, but the molecular pattern remained unchanged despite the development of drug resistance. In three patients, the DRE‐PCR patterns of the isolates changed dramatically. Clinical and microbiological evidence was consistent with active tuberculosis caused by a new strain of M. tuberculosis. The exogenous reinfection of the three patients was not due to an outbreak, but the isolates from each patient showed unique patterns.
Cancer incidence in French Polynesia 1985–95
Authors: Le Vu Béatrice , de Vathaire Florent , Challeton de Vathaire Cécile , Paofaite John , Roda Laurent , Soubiran Gilles , Lhoumeau François , Laudon François 
Published: March 2003

Summary objective  To describe the variations in cancer incidence in the population born in French Polynesia (FP) according to the archipelago of birth and to compare this incidence with that of Hawaiians and Maoris. methods  Study of data from the Cancer Registry of FP, evacuation files, insurance records, hospital and pathology laboratory files. results  The overall world standardized cancer incidence in FP during the 1985–95 period in the populations born and living in FP was 246 per 105 person‐years (PY) among women and 244 per 105 PY among men. The overall cancer incidence was similar to that in Hawaiians, but 25% lower than in Maoris. Digestive tract cancer incidence was a third that of these two reference populations, whereas that of pharynx, larynx and thyroid cancers was approximately twice as high. The overall cancer incidence rate increased between the period 1985–89 and the period 1990–95 in women, but was stable in men. Colorectal cancer incidence was highest in inhabitants born on the Windward Islands. Women born on the Austral Islands had a higher thyroid and liver cancer incidence and a lower breast cancer incidence. conclusions  Further studies are needed to elucidate the variations observed between FP archipelagos, Maoris and Hawaiians.
Micronutrient and iron supplementation and effective antimalarial treatment synergistically improve childhood anaemia
Authors: Ekvall H. , Premji Z. , Björkman A. 
Published: March 2003

Summary The control of childhood anaemia in malaria holoendemic areas is a major public health challenge for which an optimal strategy remains to be determined. Malaria prevention may compromise the development of partial immunity. Regular micronutrient supplementation has been suggested as an alternative but its effectiveness remains unsettled. We therefore conducted a randomised placebo‐controlled intervention trial with 207 Tanzanian children aged 5 months to 3 years on the efficacy of supervised supplementation of low‐dose micronutrients including iron (Poly Vi‐Sol with iron) three times per week, with an average attendance of ≥ 90%. The mean haemoglobin (Hb) level increased by 8 g/l more in children on supplement (95% CI 3–12) during the 5‐month study. All age groups benefited from the intervention including severely anaemic subjects. The mean erythrocyte cell volume (MCV) increased but Hb in children ≥ 24 months improved independently of MCV and no relation was found with hookworm infection. The data therefore suggest that micronutrients other than iron also contributed to Hb improvement. In the supplement group of children who had received sulfadoxine‐pyrimethamine (SP) treatment, the mean Hb level increased synergistically by 22 g/l (95% CI 13–30) compared to 7 g/l (95% CI 3–10) in those without such treatment. Supplementation did not affect malaria incidence. In conclusion, micronutrient supplementation improves childhood anaemia in malaria holoendemic areas and this effect is synergistically enhanced by temporary clearance of parasitaemia.
Process indicators for safe motherhood programmes: their application and implications as derived from hospital data in Nepal
Authors: Pathak Laxmi R. , Kwast Barbara E. , Malla Dibya S. , Pradhan Ajit S. , Rajlawat Radhika , Campbell Bruce B. 
Published: March 2003

Summary Measuring maternal mortality ratios is fraught with problems and underestimates. Therefore process indicators have been proposed for monitoring the availability and use of obstetrics services. We report the results of process indicators for measuring the availability, use and quality of obstetric care in five districts in Nepal between 1997 and 1998. The number of comprehensive essential obstetric care (EOC) facilities was adequate for four of the five districts, but none had a minimum acceptable level of basic EOC facilities as set by UNICEF et al. The proportion of expected births in hospital was 21.5% in Rupandehi and < 5% in Baglung, Kailali, Okhaldunga and Surkhet. The minimum acceptable level is 15%. The ‘met need’ for obstetric care which pertains to the proportion of all women with direct obstetric complications that are treated in hospital was 14.9% in Rupandehi and < 5% in the other four districts, against the required minimum of 15%. The caesarean section rate calculated of all expected births in the population varied between 0.2% and 1.4%. The case fatality rate was 4.0% in Rupandehi Zonal Hospital. Analysis of these indicators clearly identified tremendous underuse of maternity services which has stimulated national policy discussions in Nepal with ensuing safe motherhood interventions and monitoring strategies.