bluuebunny/crossref_metadata_2025_split huggingface dataset:
De‐submergence‐induced ethylene production in Rumex palustris: regulation and ecophysiological significance
Authors: Voesenek L. A. C. J. , Jackson M. B. , Toebes A. H. W. , Huibers W. , Vriezen W. H. , Colmer T. D. 
Published: March 2003

Summary Rumex palustris responds to total submergence by increasing the elongation rate of young petioles. This favours survival by shortening the duration of submergence. Underwater elongation is stimulated by ethylene entrapped within the plant by surrounding water. However, abnormally fast extension rates were found to be maintained even when leaf tips emerged above the floodwater. This fast post‐submergence growth was linked to a promotion of ethylene production that is presumed to compensate for losses brought about by ventilation. Three sources of ACC contributed to post‐submergence ethylene production in R. palustris: (i) ACC that had accumulated in the roots during submergence and was transported in xylem sap to the shoot when stomata re‐opened and transpiration resumed, (ii) ACC that had accumulated in the shoot during the preceding period of submergence and (iii) ACC produced de novo in the shoot following de‐submergence. This new production of ethylene was associated with increased expression of an ACC synthase gene (RP‐ACS1) and an ACC oxidase gene (RP‐ACO1), increased ACC synthase activity and a doubling of ACC oxidase activity, measured in vitro. Out of seven species of Rumex examined, a de‐submergence upsurge in ethylene production was seen only in shoots of those that had the ability to elongate fast when submerged.
Histone modifications in Arabidopsis– high methylation of H3 lysine 9 is dispensable for constitutive heterochromatin
Authors: Jasencakova Zuzana , Soppe Wim J. J. , Meister Armin , Gernand Dorota , Turner Bryan M. , Schubert Ingo 
Published: March 2003

SummaryN‐terminal modifications of nucleosomal core histones are involved in gene regulation, DNA repair and recombination as well as in chromatin modeling. The degree of individual histone modifications may vary between specific chromatin domains and throughout the cell cycle. We have studied the nuclear patterns of histone H3 and H4 acetylation and of H3 methylation in Arabidopsis. A replication‐linked increase of acetylation only occurred at H4 lysine 16 (not for lysines 5 and 12) and at H3 lysine 18. The last was not observed in other plants. Strong methylation at H3 lysine 4 was restricted to euchromatin, while strong methylation at H3 lysine 9 occurred preferentially in heterochromatic chromocenters of Arabidopsis nuclei. Chromocenter appearance, DNA methylation and histone modification patterns were similar in nuclei of wild‐type and kryptonite mutant (which lacks H3 lysine 9‐specific histone methyltransferase), except that methylation at H3 lysine 9 in heterochromatic chromocenters was reduced to the same low level as in euchromatin. Thus, a high level of H3methylK9 is apparently not necessary to maintain chromocenter structure and does not prevent methylation of H3 lysine 4 within Arabidopsis chromocenters.
Cell wall pectic (1→4)‐β‐d‐galactan marks the acceleration of cell elongation in the Arabidopsis seedling root meristem
Authors: McCartney Lesley , Steele‐King Clare G. , Jordan Emillie , Knox J. Paul 
Published: March 2003

SummaryHere we demonstrate that the pectic rhamnogalacturonan‐I‐associated LM5 (1→4)‐β‐d‐galactan epitope occurs in a restricted manner at the root surface of intact Arabidopsis seedlings. The root surface occurrence of (1→4)‐β‐d‐galactan marks the transition zone at or near the onset of rapid cell elongation and the epitope is similarly restricted in occurrence in epidermal, cortical and endodermal cell walls. The extent of surface (1→4)‐β‐d‐galactan occurrence is reduced in response to genetic mutations (stp‐1, ctr‐1) and hormone applications that reduce root cell elongation. In contrast, the application of the arabinogalactan‐protein (AGP) binding β‐glucosyl Yariv reagent (βGlcY) that disrupts cell elongation results in the persistence of (1→4)‐β‐d‐galactan at the root surface and in epidermal, cortical and endodermal cell walls. This latter observation indicates that modulation of pectic (1→4)‐β‐d‐galactan may be an event downstream of AGP function during cell expansion in the Arabidopsis seedling root.
Global expression profiling of sulfur‐starved Arabidopsis by DNA macroarray reveals the role of O‐acetyl‐l‐serine as a general regulator of gene expression in response to sulfur nutrition
Authors: Hirai Masami Yokota , Fujiwara Toru , Awazuhara Motoko , Kimura Tomoko , Noji Masaaki , Saito Kazuki 
Published: March 2003

SummaryTo investigate the changes in profiles of mRNA accumulation in response to sulfur deficiency, approximately 13 000 non‐redundant Arabidopsis thaliana ESTs corresponding to approximately 9000 genes were analyzed using DNA macroarray. Three‐week‐old Arabidopsis plants grown on an agarose‐solidified control medium were transferred to a sulfate‐free medium and grown for 48 h for the analyses of sulfur‐related metabolites and global gene expression profiles. Concentrations of sulfate, O‐acetyl‐l‐serine (OAS), a positive regulator of sulfur deficiency‐responsive genes, cysteine and glutathione (GSH) were determined. Plants transferred to sulfate‐free media had reduced concentrations of sulfate and GSH, and OAS concentrations increased. Macroarray analysis revealed a number of genes, including APR2 and Sultr1;2, whose mRNA accumulation was increased by sulfur deficiency. Profiling was also carried out with plants treated with OAS under sulfate‐sufficient condition. Scatter plot analysis revealed a positive correlation between the changes of expression levels by sulfur deficiency and by OAS treatment among the clones tested, suggesting that mRNA accumulation of a number of genes under sulfur deficiency is mainly controlled by OAS concentrations in tissues. It was also revealed that the sets of genes regulated under sulfur deficiency in leaves and roots differ considerably.
Brassinosteroid functions in a broad range of disease resistance in tobacco and rice
Authors: Nakashita Hideo , Yasuda Michiko , Nitta Takako , Asami Tadao , Fujioka Shozo , Arai Yuko , Sekimata Katsuhiko , Takatsuto Suguru , Yamaguchi Isamu , Yoshida Shigeo 
Published: March 2003

SummaryBrassinolide (BL), considered to be the most important brassinosteroid (BR) and playing pivotal roles in the hormonal regulation of plant growth and development, was found to induce disease resistance in plants. To study the potentialities of BL activity on stress responding systems, we analyzed its ability to induce disease resistance in tobacco and rice plants. Wild‐type tobacco treated with BL exhibited enhanced resistance to the viral pathogen tobacco mosaic virus (TMV), the bacterial pathogen Pseudomonas syringae pv. tabaci (Pst), and the fungal pathogen Oidium sp. The measurement of salicylic acid (SA) in wild‐type plants treated with BL and the pathogen infection assays using NahG transgenic plants indicate that BL‐induced resistance does not require SA biosynthesis. BL treatment did not induce either acidic or basic pathogenesis‐related (PR) gene expression, suggesting that BL‐induced resistance is distinct from systemic acquired resistance (SAR) and wound‐inducible disease resistance. Analysis using brassinazole 2001, a specific inhibitor for BR biosynthesis, and the measurement of BRs in TMV‐infected tobacco leaves indicate that steroid hormone‐mediated disease resistance (BDR) plays part in defense response in tobacco. Simultaneous activation of SAR and BDR by SAR inducers and BL, respectively, exhibited additive protective effects against TMV and Pst, indicating that there is no cross‐talk between SAR‐ and BDR‐signaling pathway downstream of BL. In addition to the enhanced resistance to a broad range of diseases in tobacco, BL induced resistance in rice to rice blast and bacterial blight diseases caused by Magnaporthe grisea and Xanthomonas oryzae pv. oryzae, respectively. Our data suggest that BDR functions in the innate immunity system of higher plants including dicotyledonous and monocotyledonous species.
Assessment of the potential of plasma fractionation processes to remove causative agents of transmissible spongiform encephalopathy
Authors: Foster  
Published: March 2003

Although there is no evidence that classical CJD (cCJD) can be transmitted by human blood or blood products in clinical practice, uncertainties surrounding new variant CJD (nvCJD) have led to the safety of plasma products derived from UK donors being questioned. To better define whether or not there is a risk of nvCJD being transmitted it is necessary to determine how the causative agent would partition across the separations processes used in the preparation of plasma products.The abnormal prion protein which is associated with transmissible spongiform encephalopathies (TSEs), such as CJD, has a low solubility, a high tendency to form aggregates and adheres to surfaces readily. If the physicochemical properties of the agent of nvCJD are similar to those of abnormal prion protein then nvCJD may be removed by precipitation and adsorption technologies used in plasma fractionation.Available data on the removal of TSE agents by such bioprocess technologies have been used to estimate the potential degree of reduction expected from each step in the plasma fractionation processes used by the SNBTS. The overall process reduction factors estimated are: 1013 (albumin), 109 (immunoglobulins), 107 (factor IX, thrombin), 105 (fibrinogen), 104 (factor VIII) and 103 (factor II, IX and X); however, it will be necessary to establish the accuracy of these estimates by practical validation studies.
Comparison of low ionic diluents for use with the Diamed antiglobulin gel test
Authors: Grey D. , Connolly M. , Erber W. N. 
Published: March 2003

Summary Microtube column systems, although widely used in transfusion serology for the detection of red cell antibodies, may not detect weak Fya, Jka, S and K antibodies. A number of low ionic diluents are used to shorten the incubation time required for red cell antibody detection in the antiglobulin test. However, there are no published reports to show whether these low ionic diluents vary in their ability to detect red cell antibodies using microcolumn detection systems. Three low ionic diluents, Diamed ID‐CellStab, Diamed ID‐Diluent2 and an in‐house produced low ionic strength solution (LISS), were assessed using the Diamed‐ID LISS/Coombs microtube column system (in accordance with the manufacturer's instructions), to ascertain whether the choice of diluent influences red cell antibody detection.Two hundred and seventy patient samples were screened for red cell antibodies. The reaction strength was increased in 50% of the samples with detectable red cell antibodies using LISS as the diluent compared with ID‐CellStab. Of the 51 red cell antibodies directed against Rhesus, Duffy, Kidd or Kell antigens, 21% reacted more strongly in LISS compared with Diamed ID‐CellStab with a difference in grading of ≥1. Minimal disparity was found between ID‐Diluent2 and LISS.Biochemical analysis of pH, osmolality, sodium, potassium and phosphate were comparable for ID‐CellStab, ID‐Diluent2 and LISS. Measurement of conductivity in each low ionic diluent was performed as a measure of ionic strength in the final reactant mix, as the same amount of low ionic diluent was used for each test. The conductivity was 3·5 mS cm for LISS and ID‐Diluent2, and 5·8 mS cm for ID‐CellStab; the acceptable range being 3·7 ± 0·3 mS cm as cited in the Guidelines for the Blood Transfusion Services in the United Kingdom.This evaluation suggests that ID‐CellStab is a suboptimal low ionic diluent for red cell antibody detection using Diamed‐ID LISS/Coombs gel cards. The poorer performance of ID‐CellStab compared with LISS may be explained by its higher ionic strength.
An investigation into the interaction between drug efficacy and drug price of praziquantel in determining the cost‐effectiveness of school‐targeted treatment for Schistosoma mansoni using a population dynamic model
Authors: Guyatt Helen L. , Chan Man‐Suen 
Published: March 2003

SummarySummaryA population dynamic model of schistosome transmission was used to investigate the interaction between drug efficacy and drug price of different brands of praziquantel in determining the cost‐effectiveness of school‐targeted treatment for Schistosoma mansoni. In this analysis, costs were affected by coverage, drug price and distance travelled, and effectiveness by coverage and drug efficacy. Four effectiveness measures were assessed: the number of infection case‐years prevented, heavy infection case‐years prevented, hepatomegaly case‐years prevented and fibrosis case‐years prevented. The interactions between drug efficacy and drug price were complex. In particular, there was a highly nonlinear relationship between drug efficacy and cost‐effectiveness, with drugs of low efficacy producing high and variable cost‐effectiveness ratios, particularly when other programme costs related to distance travelled were high. The results suggest that given the current price range of praziquantel, a drug with less than a 50% chance of killing the worms is not to be recommended. This has important practical implications for the widespread use of praziquantel, since most international agencies procure praziquantel purely on the basis of price. There is clearly a need for studies which evaluate the efficacy of new brands of praziquantel, and more credence should be given to the use of high efficacy brands, not only in terms of maximizing the cost‐effectiveness of the intervention programme, but also in delaying the onset of drug resistance.
Attitude towards CATT‐positive individuals without parasitological confirmation in the African Trypanosomiasis (T.b. gambiense) focus of Quiçama (Angola)
Authors: Simarro P. P. , Ruiz J. A. , Franco J. R. , Josenando T. 
Published: March 2003

Summary Serologically positive individuals without parasitological confirmation constitute an important problem for trypanosomiasis control programmes because of epidemiological and therapeutical consequences. In July 1997, in the focus of Quiçama (Angola), 4753 individuals were screened using CATT/T.b.gambiense on whole blood. In CATT‐positive but parasite‐negative individuals, CATT titration on serum was performed. Sixteen individuals showing an end‐titre lower than 1/4 were considered noninfected according to the results of a previous study of serological status of parasitologically confirmed cases; 86 individuals with end titres ≥ 1/4 were considered suspected of trypanosomiasis and were followed‐up from July 1997 to July 1998 with controls every three months. After one year, 32 individuals whose antibody titres dropped < 1/4 were considered noninfected, 22 were confirmed by demonstration of parasites, 17 were further followed‐up because antibody titres remained ≥ 1/8 but parasites could not be found. Fifteen individuals did not show up for testing. Following the usual criterion, only parasitologically confirmed cases were treated. However, if it had been decided to treat parasite‐negative individuals with a CATT end‐titre > 1/8, 22 initially unconfirmed but infected individuals would have been treated earlier, whereas 5 noninfected individuals would have been treated unnecessarily. CATT titration on diluted serum or plasma is useful for making therapeutical decisions.
Seroepidemiology of human plague in the Madagascar highlands
Authors: Ratsitorahina M. , Rabarijaona L. , Chanteau S. , Boisier P. 
Published: March 2003

Summary We conducted a seroepidemiological survey of human plague in the general population using random sampling in the area of Ambositra, the main focus of plague in the central highlands of Madagascar (520 confirmed and presumptive cases notified during the past 10 years). Sera were tested using an ELISA IgG F1 assay. Considering the internal validity of the assay and the sampling method, the overall corrected prevalence of F1 antibodies was 0.6% (95% CI: 0.2%‐1.8%). Being nearly 0 up to the age of 40, the corrected prevalence increased markedly after 45 years to 6.2%. Six of 20 individuals who declared to have been treated for clinical suspicion of bubonic plague in the past had F1 antibodies. The seroprevalence did not differ according to gender except in individuals > 60, where antibodies were significantly more frequent in males. This study suggests that the number of clinically suspected cases of plague provided by the surveillance network was plausible, despite some true cases being missed and a significant number of false positives. We also confirm that Yersinia pestis infections may occur without marked clinical manifestations and patients may recover without treatment, in accordance with old observations of pestis minor.
Salmonella enteritidis diarrhoea in Harare, Zimbabwe
Authors: Simango Clifford , Mbewe Charity 
Published: March 2003

Summary The study was conducted to determine the prevalence of Salmonella enteritidis diarrhoea in an urban area in Zimbabwe. Stool specimens from people of all ages presenting at primary level health centres in Harare were investigated for S. enteritidis and other bacterial and parasitic enteric pathogens. The first 46 S. enteritidis isolates were phage‐typed, and all isolates were tested for susceptibility to ampicillin (10 μg), chloramphenicol (30 μg), cotrimoxazole (25 μg), tetracycline (30 μg), gentamicin (10 μg), nalidixic acid (30 μg), ciprofloxacin (5 μg) and ceftriaxone (30 μg). S. enteritidis was isolated in 74 (1.8%) of 4155 stool specimens which represented 30.7% of all Salmonella species isolated. The most common S. enteritidis phage type was 4 (78.3%) followed by 7, 9 and 23 (8.7%, 2.2%, 2.2%, respectively) All S. enteritidis isolates were sensitive to gentamicin, ciprofloxacin and ceftriaxone. Less than 10% of the isolates were resistant to the other antimicrobials except ampicillin, to which 13.5% were resistant. One isolate was resistant to ampicillin, chloramphenicol, cotrimoxazole and nalidixic acid.
Leishmaniasis in the Sudan: a literature review with emphasis on clinical aspects
Authors: Osman Omran F. , Kager Piet A. , Oskam Linda 
Published: March 2003

SummaryThe literature on the leishmaniases in the Sudan is reviewed with an emphasis on clinical aspects and on literature related to the recent outbreaks in the south and east of the country. The numbers of cases of subclinical infection and post‐kala azar dermal leishmaniasis in the recent outbreaks are remarkable. New diagnostic techniques have been introduced and evaluated, notably the direct agglutination test and polymerase chain reaction technology. The latter gives very promising results and further research into application of the technique is warranted. Treatment with pentavalent antimony is still satisfactory. The reservoir host has not been identified definitely.
Hepatitis B infection and aflatoxin biomarker levels in Gambian children
Authors: Turner P. C. , Mendy M. , Whittle H. , Fortuin M. , Hall A. J. , Wild C. P. 
Published: March 2003

Summary objectives  To examine the relationship between hepatitis B virus (HBV) infection and biomarkers of aflatoxin exposure in West African children.methods  Sera from 444 children aged 3–4 years who were selected to be representative of their communities were analysed for aflatoxin‐albumin (AF‐alb) adducts and markers of hepatitis B infection.results  There was large interindividual variation in adduct levels (range: 2.2 to 459 pg AF‐lysine eq./mg albumin). Adduct level was strongly correlated with season, with an approximately twofold higher mean level in the dry season than the wet. Geometric mean adduct levels in uninfected children, chronic carriers and acutely infected children were 31.6 (n = 404), 44.9 (n = 34) and 96.9 (n = 6) pg/mg, respectively. The relationship of AF‐alb level to ethnicity, month of sampling and HBV status was examined in a multiple regression model. Month of obtaining the blood sample (P = 0.0001) and HBV status (P = 0.0023) each made a highly significant contribution to the model; the high AF‐alb levels were particularly associated with acute infection. Elevated serum transaminase levels were significantly (P < 0.002) associated with HBV status, with acutely infected children having the highest levels. Ethnicity was not significantly associated with AF‐alb adduct levels in the model (P = 0.09).conclusions  HBV infection and month of sampling both significantly influence AF‐alb adduct levels. The effect of seasonality on adducts was also observed in a previous study of 347 Gambian adults, although there was no correlation between adduct level and HBV status in that population. This difference between children and adults may reflect a more severe effect of HBV infection, particularly acute infection, in childhood on hepatic AF metabolism.
Evaluation of the World Health Organization standard tourniquet test and a modified tourniquet test in the diagnosis of dengue infection in Viet Nam
Authors: Phuong Cao Xuan Thanh , Nhan Ngo Thi , Wills Bridget , Kneen Rachel , Ha Nguyen Thi Thanh , Mai Ta Thi Tuyet , Huynh Tran Thi Thanh , Lien Doan Thi Kim , Solomon Tom , Simpson Julie A. , White Nicholas J. , Farrar Jeremy J. ,   the Dong Nai Paediatric Hospital Study Group
Published: March 2003

OBJECTIVES A positive tourniquet test is one of several clinical parameters considered by the World Health Organization to be important in the diagnosis of dengue haemorrhagic fever, but no formal evaluation of the test has been undertaken. As many doctors remain unconvinced of its usefulness, this study was designed to assess the diagnostic utility of both the standard test and a commonly employed modified test. METHODS A prospective evaluation of the standard sphygmomanometer cuff tourniquet test, compared with a simple elastic cuff tourniquet test, was carried out in 1136 children with suspected dengue infection admitted to a provincial paediatric hospital in southern Viet Nam. RESULTS There was good agreement between independent observers for both techniques, but the sphygmomanometer method resulted in consistently greater numbers of petechiae. This standard method had a sensitivity of 41.6% for dengue infection, with a specificity of 94.4%, positive predictive value of 98.3% and negative predictive value of 17.3%. The test differentiated poorly between dengue haemorrhagic fever (45% positive) and dengue fever (38% positive). The simple elastic tourniquet was less sensitive than the sphygmomanometer cuff, but at a threshold of 10 petechiae (compared with the WHO recommendation of 20) per 2.5 cm2 the sensitivity for the elastic tourniquet rose to 45% (specificity 85%). Other evidence of bleeding was frequently present and the tourniquet test provided additional information to aid diagnosis in only 5% of cases. CONCLUSION The conventional tourniquet test adds little to the diagnosis of dengue in hospitalized children. The simple, cheap elastic tourniquet may be useful in diagnosing dengue infection in busy rural health stations in dengue endemic areas of the tropics. A positive test should prompt close observation or early hospital referral, but a negative test does not exclude dengue infection.