bluuebunny/crossref_metadata_2025 huggingface dataset:
Thylakoid membrane‐bound ascorbate peroxidase is a limiting factor of antioxidative systems under photo‐oxidative stress
Authors: Yabuta Yukinori , Motoki Takashi , Yoshimura Kazuya , Takeda Toru , Ishikawa Takahiro , Shigeoka Shigeru
Published: March 2003

To evaluate the physiological importance of thylakoid membrane‐bound ascorbate peroxidase (tAPX) in the active oxygen species‐scavenging system of chloroplasts, the level of tAPX in tobacco plants was altered by expression of the tAPX cDNA in both sense and antisense orientation. The tobacco plants transformed with constructs of antisense tAPXs from spinach and tobacco could not be obtained, suggesting that the suppression of tAPX in higher plants had a severe effect on the growth even under normal conditions. In contrast, the transgenic tobacco plants (TpTAP‐12) overexpressing tAPX, which had approximately 37‐fold higher activity than that of the wild‐type plants, were generated. The TpTAP‐12 plants showed increased tolerance to oxidative stress caused by application of methylviologen (MV, 50 µm) under light intensity (300 and 1600 µE m−2 sec−1) and by chilling stress with high light intensity (4°C, 1000 µE m−2 sec−1). At 24 h after the MV treatment under illumination at 300 µE m−2 sec−1, destruction of chlorophyll was observed in the wild‐type plants, but not in the TpTAP‐12 plants. The activities of thiol‐modulated enzymes in the Calvin cycle, the level and redox status of ascorbate (AsA), and the activity of tAPX in the wild‐type plants significantly decreased, while those in the TpTAP‐12 plants were hardly changed. These observations suggest that tAPX is a limiting factor of antioxidative systems under photo‐oxidative stress in chloroplasts, and that the enhanced activity of tAPX functions to maintain the AsA content and the redox status of AsA under stress conditions.
Arabidopsis is susceptible to the cereal ear blight fungal pathogens Fusarium graminearum and Fusarium culmorum
Authors: Urban Martin , Daniels Steve , Mott Ellie , Hammond‐Kosack Kim
Published: March 2003

The fungal pathogens Fusarium graminearum and F. culmorum cause ear blight disease on cereal crops worldwide. The disease lowers both grain quality and grain safety. Disease prevalence is increasing due to changes in cropping practices and the difficulties encountered by plant breeders when trying to introgress the polygene‐based resistance. The molecular basis of resistance to Fusarium ear blight in cereal species is poorly understood. This is primarily due to the large size of cereal genomes and the expensive resources required to undertake gene function studies in cereals. We therefore explored the possibility of developing various model floral infection systems that would be more amenable to experimental manipulation and high‐throughput gene function studies. The floral tissues of tobacco, tomato, soybean and Arabidopsis were inoculated with Fusarium conidia and this resulted in disease symptoms on anthers, anther filaments and petals in each plant species. However, only in Arabidopsis did this initial infection then spread into the developing siliques and seeds. A survey of 236 Arabidopsis ecotypes failed to identify a single genotype that was extremely resistant or susceptible to Fusarium floral infections. Three Arabidopsis floral mutants that failed to develop anthers and/or functional pollen (i.e. agamous‐1, apetala1–3 and dad1) were significantly less susceptible to Fusarium floral infection than wild type. Deoxynivalenol (DON) mycotoxin production was also detected in Fusarium‐infected flowers at >1 ppm. This novel floral pathosystem for Arabidopsis appears to be highly representative of a serious cereal crop disease.
Cell cycle progression during endosperm development in Zea mays depends on parental dosage effects
Authors: Leblanc Olivier , Pointe Céline , Hernandez Martha
Published: March 2003

Interploidy crosses in flowering plants often cause seed abortion. Studies in maize have shown that failure of kernel development results from dosage effects among products of imprinted but as‐yet‐unknown genes in the endosperm, and that the operative stoichiometry is established for a ratio of two maternal genomes to one paternal genome. In this study, we used flow cytometry to monitor cell cycle activities in developing endosperms obtained after reciprocal crosses between diploid and tetraploid maize individuals. Our data show that dosage effects alter critical events involved in the establishment of endoreduplication during maize endosperm development. Particularly, maternal genomic excess (4x × 2x crosses) forces endosperm cells to enter early into endoreduplication while paternal genomic excess (2x × 4x crosses) prevents its establishment. Our results also suggest that altering mechanisms depend on two different sets of cell cycle regulatory genes – one imprinted through the female that is required for mitotic arrest, and another responsible for re‐entry into S phase that is imprinted through the male. Further, molecular and physiological analyses should provide insights into the interaction of parental imprinting action and cell cycle regulation during endosperm development.
Multifunctional acetyl‐CoA carboxylase 1 is essential for very long chain fatty acid elongation and embryo development in Arabidopsis
Authors: Baud Sébastien , Guyon Virginie , Kronenberger Jocelyne , Wuillème Sylvie , Miquel Martine , Caboche Michel , Lepiniec Loïc , Rochat Christine
Published: March 2003

Acetyl‐CoA carboxylase (ACCase) catalyses the carboxylation of acetyl‐CoA, forming malonyl‐CoA, which is used in the plastid for fatty acid synthesis and in the cytosol in various biosynthetic pathways including fatty acid elongation. In Arabidopsis thaliana, ACC1 and ACC2, two genes located in a tandem repeat within a 25‐kbp genomic region near the centromere of chromosome 1, encode two multifunctional ACCase isoforms. Both genes, ACC1 and ACC2, appear to be ubiquitously expressed, but little is known about their respective function and importance. Here, we report the isolation and characterisation of two allelic mutants disrupted in the ACC1 gene. Both acc1‐1 and acc1‐2 mutations are recessive and embryo lethal. Embryo morphogenesis is impaired and both alleles lead to cucumber‐like structures lacking in cotyledons, while the shortened hypocotyl and root exhibit a normal radial pattern organisation of the body axis. In this abnormal embryo, the maturation process still occurs. Storage proteins accumulate normally, while triacylglycerides (TAG) are synthesised at a lower concentration than in the wild‐type seed. However, these TAG are totally devoid of very long chain fatty acids (VLCFA) and consequently enriched in C18:1, like all lipid fractions analysed in the mutant seed. These data demonstrate, in planta, the role of ACCase 1 in VLCFA elongation. Furthermore, this multifunctional enzyme also plays an unexpected and central function in embryo morphogenesis, especially in apical meristem development.
Biochemical and functional analysis of CTR1, a protein kinase that negatively regulates ethylene signaling inArabidopsis
Authors: Huang Yafan , Li Hui , Hutchison Claire E. , Laskey James , Kieber Joseph J.
Published: March 2003

CTR1encodes a negative regulator of the ethylene response pathway inArabidopsis thaliana. The C‐terminal domain of CTR1 is similar to the Raf family of protein kinases, but its first two‐thirds encodes a novel protein domain. We used a variety of approaches to investigate the function of these two CTR1 domains. Recombinant CTR1 protein was purified from a baculoviral expression system, and shown to possess intrinsic Ser/Thr protein kinase activity with enzymatic properties similar to Raf‐1. Deletion of the N‐terminal domain did not elevate the kinase activity of CTR1, indicating that, at leastin vitro, this domain does not autoinhibit kinase function. Molecular analysis of loss‐of‐functionctr1alleles indicated that several mutations disrupt the kinase catalytic domain, andin vitrostudies confirmed that at least one of these eliminates kinase activity, which indicates that kinase activity is required for CTR1 function. One missense mutation,ctr1–8, was found to result from an amino acid substitution within a new conserved motif within the N‐terminal domain.Ctr1–8 hasno detectable effect on the kinase activity of CTR1in vitro,but rather disrupts the interaction with the ethylene receptor ETR1. This mutation also disrupts the dominant negative effect that results from overexpression of the CTR1 amino‐terminal domain in transgenicArabidopsis. These results suggest that CTR1 interacts with ETR1in vivo, and that this association is required to turn off the ethylene‐signaling pathway.
Arabidopsis actin gene ACT7 plays an essential role in germination and root growth
Authors: Gilliland Laura U. , Pawloski Lucia C. , Kandasamy Muthugapatti K. , Meagher Richard B.
Published: March 2003

Arabidopsis contains eight actin genes. Of these ACT7 is the most strongly expressed in young plant tissues and shows the greatest response to physiological cues. Adult plants homozygous for the act7 mutant alleles show no obvious above‐ground phenotypes, which suggests a high degree of functional redundancy among plant actins. However, act7‐1 mutant plants are at a strong selective disadvantage when grown in competition with wild‐type plants and therefore must have undetected physical defects. The act7‐1 and act7‐4 alleles contain T‐DNA insertions just after the stop codon and within the first intron, respectively. Homozygous mutant seedlings of both alleles showed less than 7% of normal ACT7 protein levels. Mutants displayed delayed and less efficient germination, increased root twisting and waving, and retarded root growth. The act7‐4 mutant showed the most dramatic reduction in root growth. The act7‐4 root apical cells were not in straight files and contained oblique junctions between cells suggesting a possible role for ACT7 in determining cell polarity. Wild‐type root growth was fully restored to the act7‐1 mutant by the addition of an exogenous copy of the ACT7 gene. T‐DNA insertions just downstream of the major polyadenylation sites (act7‐2, act7‐3) appeared fully wild type. The act7 mutant phenotypes demonstrate a significant requirement for functional ACT7 protein during root development and explain the strong negative selection component seen for the act7‐1 mutant.
Transgenic expression of a putative calcium transporter affects the time of Arabidopsis flowering
Authors: Wang Dayong , Xu Yunjian , Li Qing , Hao Xuemei , Cui Keming , Sun Fangzhen , Zhu Yuxian
Published: March 2003

PPF1 is a gibberellin‐induced, vegetative growth‐specific gene, first isolated from short‐day (SD)‐grown G2 pea plants. In the current work, we found that transgenic Arabidopsis plants overexpressing the PPF1 gene (PPF1 (+)) flowered much later and had a significantly longer lifespan compared to control plants, whereas suppression of this gene (PPF1 (–)) resulted in a very rapid reproductive cycle. Western blotting analyses of PPF1 (+) and (–) plant lines revealed a positive correlation between the amount of antibody‐reactive protein and the time of flowering. Green flourescent protein (GFP) co‐expression assays showed that the PPF1 protein is likely localized in chloroplast membranes. Transgenic expression of PPF1 affected the calcium storage capacities since chloroplasts isolated from PPF1 (+) plants contained high Ca2+ levels while chloroplasts of PPF1 (–) plants contained very low amounts of calcium ion. Using Novikoff human hepatoma cells, we demonstrated that expression of PPF1 leads to a significant inward calcium ion current that was absent in untransformed cells. We conclude that, as a putative calcium ion carrier, PPF1 affects the flowering time of higher plants by modulating Ca2+ storage capacity within chloroplasts.
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

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

N‐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

Here 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

To 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

Brassinolide (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.
Evaluation of plasma and red cells obtained after leucocyte depletion of whole blood
Authors: Williamson  , Rider  , Swann  , Winter  , Ali  , Pamphilon
Published: March 2003

We evaluated whole blood integral filtration to produce leucocyte‐depleted red cells and plasma by using the WBF1 whole blood filter (Pall Medsep). Whole blood units were filtered after either warm (2–4 h at room temperature) or cold (12–24 h at 4 °C) holds. Filtered and control units were processed using either a bottom‐and‐top or top‐top method. Red cells were tested weekly for 6 weeks, and plasma 3 monthly for 12 months. All filtered red‐cell packs contained < 5 × 106 leucocytes/unit with 71 of 72 containing < 1 × 106 leucocytes/unit. No clinically significant differences in red‐cell storage parameters were seen, although haemolysis was less and pO2/pCO2 values were better maintained in filtered units. Plasma units contained < 2.5 × 103 leucocytes/unit with no significant loss of factor VIII except in the warm hold units processed by the top‐top method. There was no evidence of complement or coagulation activation with significant removal of preformed C3a in cold hold units. Plasma storage parameters were maintained at control levels for 12 months.
Effect of premedication guidelines and leukoreduction on the rate of febrile nonhaemolytic platelet transfusion reactions
Authors: Patterson  , Freedman  , Blanchette  , Sher  , Pinkerton  , Hannach  , Meharchand  , Lau  , Boyce  , Pinchefsky  , Tasev  , Pinchefsky  , Poon  , Shulman  , Mack  , Thomas  , Blanchette  , Greenspan  , Panzarella
Published: March 2003

Platelet transfusion reactions were prospectively studied in haematology/oncology patients at five university teaching hospitals over three consecutive summers. The initial summer study provided baseline information on the use of premedications and the rate of platelet transfusion reactions (fever, chills, rigors and hives). Most (73%) platelet recipients were premedicated and 30% (95% CI 28–33%) of transfusions were complicated by reactions. The second study followed implementation of guidelines for premedicating platelet transfusions. Despite a marked reduction in premedication (50%), there was little change in the platelet transfusion reaction rate, 26% (95% CI 24–29%), or the type of reactions. The third study followed implementation of prestorage platelet leukoreduction while maintaining the premedication guidelines. The reaction rate decreased to 19% (95% CI 17–22%). For nonleukoreduced platelets, there was a statistically significant association between the platelet age and reaction rate (P = 0.04). For leukoreduced platelets, there was no statistically significant association between platelet age and reaction rate (P = 0.5). Plasma reduction of nonleukoreduced platelet products also reduced the reaction rate. These prospective studies document a high rate of platelet transfusion reactions in haematology/oncology patients and indicate premedication use can be reduced without increasing the reaction rate. Prestorage leukoreduction and/or plasma reduction of platelet products reduces but does not eliminate febrile nonhemolytic platelet transfusion reactions.
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.
Tick‐borne diseases in transfusion medicine
Authors: Pantanowitz L. , Telford S. R. , Cannon M. E.
Published: March 2003

SummaryTicks are effective vectors of viral, bacterial, rickettsial and parasitic diseases. Many of the tick‐borne diseases (TBDs) are of significance to transfusion medicine, either because of the risks they pose to the blood supply or the necessity for blood products required in their treatment. The transmission of tick‐borne pathogens via blood transfusion is of global concern. However, among transfusion medicine practitioners, experience with most of these microorganisms is limited. Transfusion transmission of TBDs has been documented largely by means of single case reports. A better understanding of the epidemiology, biology and management of this group of diseases is necessary in order to assess the risks they pose to the blood supply and to help guide effective prevention strategies to reduce this risk. Unique methods are required to focus on donor selection, predonation questioning, mass screening and inactivation or eradication procedures. The role of the transfusion medicine service in their treatment also needs to be better defined. This article reviews the growing body of literature pertaining to this emerging field of transfusion medicine and offers some recommendations for transfusionists in dealing with TBDs.
Recurrence of kala‐azar after PKDL: role of co‐factors
Authors: Nandy A. , Addy M. , Maji A. K. , Guha S. K. , Banerjee D. , Chaudhuri D.
Published: March 2003

Recurrence of kala‐azar after post kala‐azar dermal leishmaniasis (PKDL) has remained uncommon. We report here two patients with recurrence of kala‐azar (KA) after development of PKDL. In one case the second attack of KA was preceded by repeated attacks of malaria and tuberculosis, and in the other the recurrence of KA followed an attack of measles. While measles has earlier been suggested as co‐factor in inducing transformation from sub‐clinical to clinical kala‐azar, malaria was demonstrated to enhance the virulence and invasiveness of Leishmania in an experimental model as well as under natural condition. We propose that in our cases, measles and repeated attacks of malaria or tuberculosis led to immunosuppression and recurrence of visceral leishmaniasis (VL).
Causes of locomotor disability and need for orthopaedic devices in a heavily mined Taliban‐controlled province of Afghanistan: issues and challenges for public health managers
Authors: François Isabelle , Lambert Marie‐Laurence , Salort Cécile , Slypen Vincent , Bertrand Françoise , Tonglet René
Published: March 2003

We conducted a locomotor disability survey on a heavily mined Taliban‐controlled province of Afghanistan to document the problem of locomotor disability and to assess the need for orthopaedic rehabilitation devices in a study population of 12065. Global prevalence of locomotor disability was 23/1000 (95% CI: 20–26). War‐related injuries were the leading cause of disability, affecting almost exclusively adult males. Leading causes of disability among women and children were medical and poliomyelitis. Devices most needed were lower limb ortheses (8.2 devices/1000 people; 95% CI: 5.9–10.4) and orthopaedic shoes (6.0/1000; 95% CI:4.1–8.0). The need for lower limb prostheses was less frequent (2.0/1000; 95% CI: 1.1–2.8). Most lower limb amputees (mainly victims of landmine injuries) were fitted with an artificial leg, while rehabilitation needs for other types of disability remained largely unmet. We estimated that it would take at least 3 years to provide enough orthopaedic shoes and 10 years for ortheses, whereas the need for lower limb prostheses could be met in less than 4 months. None of the 27 women with lower limb disability were equipped with an orthopaedic device, although this was the case for 31 of 89 men (35%). The problem of landmines should not divert attention from other causes of disability such as poliomyelitis or from other rehabilitation requirements. Immunization programmes and restoration of the public health infrastructure should be given high priority; rehabilitation services are largely insufficient and should be developed. Extreme gender difference in needs coverage is a matter of concern. Researching culturally sensitive strategies to tackle this problem should be a priority for donors and implementing agencies.
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

SummaryA 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.
Effect of motorcycle rider education on changes in risk behaviours and motorcycle‐related injuries in rural Thailand
Authors: Swaddiwudhipong Witaya , Boonmak Chid , Nguntra Patchree , Mahasakpan Pranee
Published: March 2003

A community‐based programme for motorcycle rider education was provided for motorcyclists in all villages of 3 randomly selected subdistricts in Mae Sot District, Tak Province, northern Thailand, between January and March 1995. To determine the extent of changes in risk‐taking behaviours, we conducted an interview survey of motorcyclists in 3 villages selected by systematic sampling from the 3 intervention subdistricts and in 3 control (without intervention) villages for comparison in March 1997, 2 years after the programme. Motorcyclists in the intervention villages (69.7%) were significantly more likely to have valid licences than those in the control villages (46.5%). The proportion of motorcyclists who always or often wore helmets was significantly greater in the intervention sample (46.0%) than in the control sample (20.5%). In 1994, the annual incidence rate of motorcycle‐related injuries was slightly higher in the intervention areas than in the control areas. Following the education programme, the injury rates for 1995 and 1996 were significantly lower in the intervention than in the control population. The annual number and rate of fatal motorcycle injuries decreased after the intervention although there was no significant difference between the two populations. Motorcycle rider education may be a promising intervention for prevention of motorcycle‐related injuries in rural areas where road safety measures, particularly enforcement activities, are commonly limited.
Survey among survivors of the 1995 Ebola epidemic in Kikwit, Democratic Republic of Congo: their feelings and experiences
Authors: De Roo Ann , Ado Bwaka , Rose Berthe , Guimard Yves , Fonck Karolien , Colebunders Robert
Published: March 2003

Summary This study describes experiences of the survivors of the 1995 Ebola epidemic in Kikwit, Democratic Republic of Congo. Most of the survivors in our sample had cared for a sick family member before becoming ill themselves, and most had never heard of Ebola before they developed symptoms and therefore did not suspect that they were infected by the virus. Fear, denial and shame were their principal initial feelings. After release from hospital, survivors were abandoned by family or friends more often than they had expected. Belief in god was an important aid to all of them. Their most negative experiences were witnessing other people dying in the isolation ward of the Kikwit General Hospital, and the reluctance of hospital personnel to treat them. During Ebola outbreaks more attention should be given to the psychosocial implications of such an epidemic. Information campaigns should include antidiscrimination messages and more psychosocial support should be given to patients and their families.
Bancroftian filariasis in an irrigation project community in southern Ghana
Authors: Dzodzomenyo Mawuli , Simonsen Paul E.
Published: March 2003

Summary An epidemiological study to document the endemicity and transmission characteristics of bancroftian filariasis was conducted in an irrigation project community in southern Ghana. In a 50% random sample of the population, the prevalence of microfilaraemia was 26.4% and the geometric mean microfilarial intensity among positives was 819 microfilariae/ml of blood. Hydrocoele was found in 13.8% of the males aged >18 years, and 1.4% of the residents examined, all females, had lymphoedema/elephantiasis. Detailed monitoring of the microfilarial intensity in 8 individuals over a 24‐h period confirmed its nocturnal periodicity with a peak at approximately 0100 hours. The most important vector was Anopheles gambiae s.l., followed by An. funestus. The abundance of these mosquitoes and their relative importance as vectors varied considerably between the wet and the dry season. Opening of the irrigation canals late in the dry season resulted in a remarkable increase in the population of An. gambiae (8.3% of which carried infective filarial larvae) to levels comparable to those seen during the wet season, suggesting that the irrigation project is responsible for increased transmission of lymphatic filariasis in the community.
Urinary schistosomiasis among schoolchildren in Ibadan, an urban community in south‐western Nigeria
Authors: Okoli E. I. , Odaibo A. B.
Published: March 2003

Summary The current status of urinary schistosomiasis was assessed in Ibadan, an urban community in south‐western Nigeria. Of 1331 children examined for eggs of S. haematobium in their urine, 17.4% were infected. Prevalence in postprimary schoolchildren was significantly (P < 0.01) higher (22.4%) than in primary schoolchildren (12.0%). Intensity of infection based on geometric mean egg count per 10 ml of urine was also higher in postprimary (36.7 eggs/10 ml urine) than primary pupils (29.9 eggs/10 ml urine). Boys had a significantly (P < 0.01) higher infection rate (24.1%) than girls (8.5%), and the intensity of infection was also higher (P < 0.01) in males (39.0 eggs/10 ml urine) than in females (22.1 eggs/10 ml urine). The overall geometric mean intensity of infection was highest (38.8 eggs/10 ml urine) in the 11–15 years age group. 42% of infected children excreted > 50 eggs/10 ml urine. 2.2% excreted S. mansoni eggs in urine. Water contact activities were more frequent (P < 0.01) in males (31.8%) than females (38.2%). Nine species of snails were encountered, with B. (p) globosus being the the most abundant and widespread. These results show that urinary schistosomiasis is still being actively being transmitted in Ibadan.
The behaviour of health workers in an era of cost sharing: Ghana's drug cash and carry system
Authors: Asenso‐Okyere W. K. , Osei‐Akoto Isaac , Anum Adote , Adukonu Augustina
Published: March 2003

Summary This qualitative study aimed to assess possible changes in prescription patterns and resultant implications for the quality of care delivered in three southern districts of Ghana after the introduction of a full cost recovery scheme for drugs in 1992. While the availability of safe and effective drugs has improved especially in rural areas, not all patients are able to meet the cost for required medication. This has influenced the behaviour of most prescribers, who now take economical limitations into account. As a result, poorer patients may either take fewer drugs or smaller quantities than medically indicated, with possible ensuing consequences for public health. Overall, the cash‐and‐carry scheme does not appear to have changed health workers' attitudes towards patients; where such behavioural changes occurred they seemed to be due to personnel shortages. Generally, patients in rural facilities reported greater satisfaction with the care they received than urban residents; and medical assistants were perceived as friendlier than both nurses and doctors.
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

The 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.
Changes in Expanded Program for Immunization coverage for mother and child in Krakor, Cambodia 1996–1998
Authors: Main Barbara , Lower Tony , James Ross , Rouse Ian
Published: March 2003

We evaluated a training intervention aimed at enhancing the roles of health centre staff, Village Health Volunteers (VHVs) and Traditional Birth Attendants (TBAs) within the Expanded Program for Immunization (EPI) in the district of Krakor, Cambodia. We conducted population‐based surveys to determine the coverage of the EPI at baseline (1996) and after the intervention (1998), using data from health cards for mothers and their children and history data. Statistically significant changes over the 2‐year period were apparent for tetanus, BCG, polio and DTP, supporting the positive impact the training intervention had on immunization coverage in the district.