bluuebunny/crossref_metadata_2025 huggingface dataset:
Mutagenic potency ofHelicobacter pyloriin the gastric mucosa of mice is determined by sex and duration of infection
Authors: Sheh Alexander , Lee Chung Wei , Masumura Kenichi , Rickman Barry H. , Nohmi Takehiko , Wogan Gerald N. , Fox James G. , Schauer David B.
Published: August 2010

Helicobacter pyloriis a human carcinogen, but the mechanisms evoked in carcinogenesis during this chronic inflammatory disease remain incompletely characterized. We determined whether chronicH. pyloriinfection induced mutations in the gastric mucosa of male and femalegptdelta C57BL/6 mice infected for 6 or 12 mo. Point mutations were increased in females infected for 12 mo. The mutation frequency in this group was 1.6-fold higher than in uninfected mice of both sexes (P< 0.05). A:T-to-G:C transitions and G:C-to-T:A transversions were 3.8 and 2.0 times, respectively, more frequent in this group than in controls. Both mutations are consistent with DNA damage induced by oxidative stress. No increase in the frequency of deletions was observed. Females had more severe gastric lesions than males at 6 mo postinfection (MPI;P< 0.05), but this difference was absent at 12 MPI. In all mice, infection significantly increased expression ofIFNγ,IL-17,TNFα, andiNOSat 6 and 12 mo, as well asH. pylori–specific IgG1 levels at 12 MPI (P< 0.05) and IgG2c levels at 6 and 12 MPI (P< 0.01 andP< 0.001). At 12 MPI, IgG2c levels in infected females were higher than at 6 MPI (P< 0.05) and also than those in infected males at 12 MPI (P< 0.05). Intensity of responses was mediated by sex and duration of infection. LowerH. pyloricolonization indicated a more robust host response in females than in males. Earlier onset of severe gastric lesions and proinflammatory, Th1-biased responses in female C57BL/6 mice may have promoted mutagenesis by exposing the stomach to prolonged oxidative stress.
Visual representation and communication
Authors: Lin Tingyi S.
Published: August 2010

There is great potential for graphics to present quantities, processes, and spatial relations that make knowledge communication more effective through simple to complex visual languages. Visual representation conveys certain messages, directly or metaphorically. An effective visual representation communicates with users by offering core messages and other embedded qualities. These embedded qualities generate interest in the topics/issues, create desirable energy for seeking more knowledge in depth, and enable readers to explore their favorable influences. It is no longer enough to consider a visual representation to be merely attractive or pleasing; it also has to be designed in a way to effectively tell stories in order to better play its role as an information carrier and to meet users’ needs for multiple modes of usage. This study examines the ways in which visual explanation both tells stories and presents their underlying meanings. Visual information design not only presents concepts and events across time but also disseminates information widely through various media. This case study investigates various visual depictions of fertility rates and observes the causes and effects of viewers’ decision making. The total fertility rates in Taiwan dropped dramatically from 1951 to 2006, according to the Department of Household Registration Affairs, Ministry of Interior (MOI), Taiwan. This drop not only will render the aging population greater than other age groups in the near future, but also greatly changes social, economic, and environmental progress in this region. This study’s small effort in the information design field will help create a link between practitioners’ intelligence and researchers’ suggestions, thereby helping enhance the effectiveness of visual communication.
Overexpression of the Victoriocin Gene inHelminthosporium(Cochliobolus)victoriaeEnhances the Antifungal Activity of Culture Filtrates
Authors: de Sá Patricia B. , Li Hua , Havens Wendy M. , Farman Mark L. , Ghabrial Said A.
Published: August 2010

We have previously reported the isolation and characterization of the broad-spectrum antifungal protein, victoriocin, from culture filtrates of a virus-infected isolate of the plant-pathogenic fungus Helminthosporium (teleomorph: Cochliobolus) victoriae. We predicted that the 10-kDa mature victoriocin is derived in vivo from a preprotoxin precursor that is processed by a signal peptidase and kexin-like endopeptidase. We also presented evidence that the victoriocin precursor is encoded by a host gene, designated the victoriocin (vin) gene. In the present study, an H. victoriae genomic DNA library was constructed in the cosmid vector pMLF-2, and a cosmid clone carrying the vin gene and flanking sequences was isolated and used to generate constructs for transformation of virus-free and virus-infected H. victoriae isolates with the vin gene. Culture filtrates of the virus-free vin transformants exhibited high levels of antifungal activity compared with that revealed by the nontransformed virus-free wild-type strain, which exhibited little or no antifungal activity. Moreover, transformation of the wild-type virus-infected H. victoriae strain with the vin gene resulted in still higher production of victoriocin and higher antifungal activity in the culture filtrates of the vin transformants compared with the virus-infected wild-type strain. As previously predicted, the presence in the vin transformants of the preprovictoriocin and its post-translationally generated products, the provictoriocin and the mature victoriocin, was clearly demonstrated. Processing of the victoriocin preprotoxin requires eukaryotic host factors because no processing occurred in an in vitro translation system or in bacteria. It is of interest that some of the virus-free isolates transformed with the vin gene exhibited some features of the virus-induced disease phenotype, including moderate stunting and sectoring. Present data suggests that victoriocin may play an indirect role in disease development. Taken together, these results indicate that victoriocin is the primary protein responsible for the antifungal activity in culture filtrates of virus-infected H. victoriae isolates and that virus infection upregulates the expression of victoriocin. Overproduction of victoriocin may give the slower-growing virus-infected fungal strains some competitive advantage by inhibiting the growth of other fungi.
Extending the Fungal Host Range of a Partitivirus and a Mycoreovirus from Rosellinia necatrix by Inoculation of Protoplasts with Virus Particles
Authors: Kanematsu Satoko , Sasaki Atsuko , Onoue Mari , Oikawa Yuri , Ito Tsutae
Published: August 2010

The potential host range of mycoviruses is poorly understood because of the lack of suitable inoculation methods. Recently, successful transfection has been reported for somatically incompatible fungal isolates with purified virus particles of two mycoviruses, the partitivirus RnPV1-W8 (RnPV1) and the mycoreovirus RnMyRV3/W370 (MyRV3), from the white root rot fungus Rosellinia necatrix (class Sordariomycetes, subclass Xylariomycetidae). These studies examined and revealed the effect of the mycoviruses on growth and pathogenicity of R. necatrix. Here, we extended the experimental host range of these two mycoviruses using a transfection approach. Protoplasts of other phytopathogenic Sordariomycetous fungi—Diaporthe sp., Cryphonectria parasitica, Valsa ceratosperma (Sordariomycetidae), and Glomerella cingulata (Hypocreomycetidae)—were inoculated with RnPV1 and MyRV3 viral particles. The presence of double-stranded RNA viral genomes in regenerated mycelia of Diaporthe sp., C. parasitica, and V. ceratosperma confirmed both types of viral infections in these three novel host species. An established RnPV1 infection was confirmed in G. cingulata but MyRV3 did not infect this host. Horizontal transmission of both viruses from newly infected strains to virus-free, wild-type strains through hyphal anastomosis was readily achieved by dual culture; however, vertical transmission through conidia was rarely observed. The virulence of Diaporthe sp., C. parasitica, and V. ceratosperma strains harboring MyRV3 was reduced compared with their virus-free counterpart. In summary, our protoplast inoculation method extended the experimental host range of RnPV1-W8 and MyRV3 within the class Sordariomycetes and revealed that MyRV3 confers hypovirulence to the new hosts, as it does to R. necatrix.
Prevalence, Incidence, and Spatial Dependence of Soybean mosaic virus in Iowa
Authors: Lu X. , Robertson A. E. , Byamukama E. , Nutter F. W.
Published: August 2010

The prevalence of soybean fields with plants infected with Soybean mosaic virus (SMV) in Iowa is assumed to be random, because the primary source of the virus is SMV-infected seed. Data collected from 2,500 soybean fields sampled over a 3-year period as part of the Iowa Soybean Disease Survey (2005 to 2007) were used to evaluate this assumption. SMV was first detected in early June of each year but counties in which it was first detected varied among years. Prevalence at the county scale at end of season was 32.3, 27.3, and 89.9% in 2005, 2006, and 2007, respectively. End-of-season incidence of SMV within SMV-positive counties was 1.5 to 25.0, 1.7 to 24, and 1.8 to 58% in 2005, 2006, and 2007, respectively. The number of fields in which plants infected with SMV were detected increased at the linear rate of approximately one new field every 2 days in 2007, compared with one new field every 22 days (2005) and 21 days (2006), with coefficients of determination (R2) of 93.2 to 96.8% using the linear model. Weak spatial dependence for end-of-season SMV incidence was detected using Moran's Index, indicating that the risk for SMV incidence at the county scale within Iowa at the end of the growing season is not random.
Early Events of Citrus Greening (Huanglongbing) Disease Development at the Ultrastructural Level
Authors: Folimonova Svetlana Y. , Achor Diann S.
Published: August 2010

Citrus greening (Huanglongbing [HLB]) is one of the most destructive diseases of citrus worldwide. The causal agent of HLB in Florida is thought to be ‘Candidatus Liberibacter asiaticus’. Understanding of the early events in HLB infection is critical for the development of effective measures to control the disease. In this work, we conducted cytopathological studies by following the development of the disease in citrus trees graft inoculated with ‘Ca. L. asiaticus’-containing material under greenhouse conditions to examine the correlation between ultrastructural changes and symptom production, with the main objective of characterizing the early events of infection. Based on our observations, one of the first degenerative changes induced upon invasion of the pathogen appears to be swelling of middle lamella between cell walls surrounding sieve elements. This anatomical aberration was often observed in samples from newly growing flushes in inoculated sweet orange and grapefruit trees at the early “presymptomatic” stage of HLB infection. Development of symptoms and their progression correlated with an increasing degree of microscopic aberrations. Remarkably, the ability to observe the bacterium in the infected tissue also correlated with the degree of the disease progression. Large numbers of bacterial cells were found in phloem sieve tubes in tissue samples from presymptomatic young flushes. In contrast, we did not observe the bacteria in highly symptomatic leaf samples, suggesting a possibility that, at more advanced stages of the disease, a major proportion of ‘Ca. L. asiaticus’ is present in a nonviable state. We trust that observations reported here advance our understanding of how ‘Ca. L. asiaticus’ causes disease. Furthermore, they may be an important aid in answering a question: when and where within an infected tree the tissue serves as a better inoculum source for acquisition and transmission of the bacterium by its psyllid vector.
Group dynamics and record signals in the ant
Temnothorax albipennis
Authors: Richardson T. O. , Christensen K. , Franks N. R. , Jensen H. J. , Sendova-Franks A. B.
Published: August 2010

Many purely physical complex systems, in which there are both stochasticity and local interactions between the components, exhibit record dynamics. The temporal statistics of record dynamics is a Poisson process operating on a logarithmic rather than a linear time scale (i.e. a log-Poisson process). Record dynamics often drive substantial changes in complex systems when new high water marks in partially stochastic processes trigger new events. Social insect colonies are exemplary complex biological systems in which many of the local interactions of the components have been moulded by natural selection for the common good. Here, we combine experimental manipulation of ant colony demography with modelling to test the hypothesis that social interactions are the mechanism underlying the record dynamics. We found that compared with the control, log-Poisson statistics were disrupted in colonies in which the pattern of interactions was modified by the removal of the brood, and disappeared completely in ‘callow’ colonies composed entirely of very young workers from the same age cohort. We conclude that a subtle interplay between the demography of the society and the pattern of the interactions between the ants is crucial for the emergence of record dynamics. This could help identify what makes an ant colony a cohesive society.
A moment invariant for evaluating the chirality of three-dimensional objects
Authors: Hattne Johan , Lamzin Victor S.
Published: August 2010

Chirality is an important feature of three-dimensional objects and a key concept in chemistry, biology and many other disciplines. However, it has been difficult to quantify, largely owing to computational complications. Here we present a general chirality measure, called the chiral invariant (CI), which is applicable to any three-dimensional object containing a large amount of data. The CI distinguishes the hand of the object and quantifies the degree of its handedness. It is invariant to the translation, rotation and scale of the object, and tolerant to a modest amount of noise in the experimental data. The invariant is expressed in terms of moments and can be computed in almost no time. Because of its universality and computational efficiency, the CI is suitable for a wide range of pattern-recognition problems. We demonstrate its applicability to molecular atomic models and their electron density maps. We show that the occurrence of the conformations of the macromolecular polypeptide backbone is related to the value of the CI of the constituting peptide fragments. We also illustrate how the CI can be used to assess the quality of a crystallographic electron density map.
In situ
ATR-IR spectroscopic and electron microscopic analyses of settlement secretions of
Undaria pinnatifida
kelp spores
Authors: Petrone L. , Easingwood R. , Barker M. F. , McQuillan A. J.
Published: August 2010

Knowledge about the settlement of marine organisms on substrates is important for the development of environmentally benign new methods for control of marine biofouling. The adhesion to substrates by spores of
Undaria pinnatifida
, a kelp species that is invasive to several countries, was studied by scanning electron and transmission electron microscopies (SEM/TEM) as well as by
in situ
attenuated total reflection infrared (ATR-IR) spectroscopy. The IR spectra showed that adhesive secretion began approximately 15 min after initial settlement and that the adhesive bulk material contained protein and anionic polysaccharides. Energy dispersive X-ray microanalysis of the adhesive identified sulphur and phosphorus as well as calcium and magnesium ions, which facilitate the gelation of the anionic polysaccharides in the sea water. The adhesive may be secreted from Golgi bodies in the spore, which were imaged by TEM of spore thin sections. Additionally, an
in situ
settlement study on TiO
2
particle film by ATR-IR spectroscopy revealed the presence of phosphorylated moieties directly binding the substrate. The presence of anionic groups dominating the adhesive suggests that inhibition of spore adhesion will be favoured by negatively charged surfaces.
A Gain-of-Function Mutation in the Arabidopsis Disease Resistance Gene RPP4 Confers Sensitivity to Low Temperature
Authors: Huang Xiaozhen , Li Jianyong , Bao Fei , Zhang Xiaoyan , Yang Shuhua
Published: August 2010

How plants adapt to low temperature is not well understood. To identify components involved in low-temperature signaling, we characterized the previously isolated chilling-sensitive2 mutant (chs2) of Arabidopsis (Arabidopsis thaliana). This mutant grew normally at 22°C but showed phenotypes similar to activation of defense responses when shifted to temperatures below 16°C. These phenotypes include yellowish and collapsed leaves, increased electrolyte leakage, up-regulation of PATHOGENESIS RELATED genes, and accumulation of excess hydrogen peroxide and salicylic acid (SA). Moreover, the chs2 mutant was seedling lethal when germinated at or shifted for more than 3 d to low temperatures of 4°C to 12°C. Map-based cloning revealed that a single amino acid substitution occurred in the TIR-NB-LRR (for Toll/Interleukin-1 receptor- nucleotide-binding Leucine-rich repeat)-type resistance (R) protein RPP4 (for Recognition of Peronospora parasitica4), which causes a deregulation of the R protein in a temperature-dependent manner. The chs2 mutation led to an increase in the mutated RPP4 mRNA transcript, activation of defense responses, and an induction of cell death at low temperatures. In addition, a chs2 intragenic suppressor, in which the mutation occurs in the conserved NB domain, abolished defense responses at lower temperatures. Genetic analyses of chs2 in combination with known SA pathway and immune signaling mutants indicate that the chs2-conferred temperature sensitivity requires ENHANCED DISEASE SUSCEPTIBILITY1, REQUIRED FOR Mla12 RESISTANCE, and SUPPRESSOR OF G2 ALLELE OF skp1 but does not require PHYTOALEXIN DEFICIENT4, NONEXPRESSOR OF PR GENES1, or SA. This study reveals that an activated TIR-NB-LRR protein has a large impact on temperature sensitivity in plant growth and survival.
The MicroRNA159-Regulated GAMYB-like Genes Inhibit Growth and Promote Programmed Cell Death in Arabidopsis
Authors: Alonso-Peral Maria M. , Li Junyan , Li Yanjiao , Allen Robert S. , Schnippenkoetter Wendelin , Ohms Stephen , White Rosemary G. , Millar Anthony A.
Published: August 2010

The microRNA159 (miR159) family represses the conserved GAMYB-like genes that encode R2R3 MYB domain transcription factors that have been implicated in gibberellin (GA) signaling in anthers and germinating seeds. In Arabidopsis (Arabidopsis thaliana), the two major miR159 family members, miR159a and miR159b, are functionally specific for two GAMYB-like genes, MYB33 and MYB65. These transcription factors have been shown to be involved in anther development, but there are differing reports about their role in the promotion of flowering and little is known about their function in seed germination. To understand the function of this pathway, we identified the genes and processes controlled by these GAMYB-like genes. First, we demonstrate that miR159 completely represses MYB33 and MYB65 in vegetative tissues. We show that GA does not release this repression and that these transcription factors are not required for flowering or growth. By contrast, in the absence of miR159, the deregulation of MYB33 and MYB65 in vegetative tissues up-regulates genes that are highly expressed in the aleurone and GA induced during seed germination. Confirming that these genes are GAMYB-like regulated, their expression was reduced in myb33.myb65.myb101 seeds. Aleurone vacuolation, a GA-mediated programmed cell death process required for germination, was impaired in these seeds. Finally, the deregulation of MYB33 and MYB65 in vegetative tissues inhibits growth by reducing cell proliferation. Therefore, we conclude that miR159 acts as a molecular switch, only permitting the expression of GAMYB-like genes in anthers and seeds. In seeds, these transcription factors participate in GA-induced pathways required for aleurone development and death.
The glabra1 Mutation Affects Cuticle Formation and Plant Responses to Microbes
Authors: Xia Ye , Yu Keshun , Navarre Duroy , Seebold Kenneth , Kachroo Aardra , Kachroo Pradeep
Published: August 2010

Systemic acquired resistance (SAR) is a form of defense that provides resistance against a broad spectrum of pathogens in plants. Previous work indicates a role for plastidial glycerolipid biosynthesis in SAR. Specifically, mutations in FATTY ACID DESATURASE7 (FAD7), which lead to reduced trienoic fatty acid levels and compromised plastidial lipid biosynthesis, have been associated with defective SAR. We show that the defective SAR in Arabidopsis (Arabidopsis thaliana) fad7-1 plants is not associated with a mutation in FAD7 but rather with a second-site mutation in GLABRA1 (GL1), a gene well known for its role in trichome formation. The compromised SAR in gl1 plants is associated with impairment in their cuticles. Furthermore, mutations in two other components of trichome development, GL3 and TRANSPARENT TESTA GLABRA1, also impaired cuticle development and SAR. This suggests an overlap in the biochemical pathways leading to cuticle and trichome development. Interestingly, exogenous application of gibberellic acid (GA) not only enhanced SAR in wild-type plants but also restored SAR in gl1 plants. In contrast to GA, the defense phytohoromes salicylic acid and jasmonic acid were unable to restore SAR in gl1 plants. GA application increased levels of cuticular components but not trichome formation on gl1 plants, thus implicating cuticle, but not trichomes, as an important component of SAR. Our findings question the prudence of using mutant backgrounds for genetic screens and underscore a need to reevaluate phenotypes previously studied in the gl1 background.
Endogenous Abscisic Acid as a Key Switch for Natural Variation in Flooding-Induced Shoot Elongation
Authors: Chen Xin , Pierik Ronald , Peeters Anton J.M. , Poorter Hendrik , Visser Eric J.W. , Huber Heidrun , de Kroon Hans , Voesenek Laurentius A.C.J.
Published: August 2010

Elongation of leaves and stem is a key trait for survival of terrestrial plants during shallow but prolonged floods that completely submerge the shoot. However, natural floods at different locations vary strongly in duration and depth, and, therefore, populations from these locations are subjected to different selection pressure, leading to intraspecific variation. Here, we identified the signal transduction component that causes response variation in shoot elongation among two accessions of the wetland plant Rumex palustris. These accessions differed 2-fold in petiole elongation rates upon submergence, with fast elongation found in a population from a river floodplain and slow elongation in plants from a lake bank. Fast petiole elongation under water consumes carbohydrates and depends on the (inter)action of the plant hormones ethylene, abscisic acid, and gibberellic acid. We found that carbohydrate levels and dynamics in shoots did not differ between the fast and slow elongating plants, but that the level of ethylene-regulated abscisic acid in petioles, and hence gibberellic acid responsiveness of these petioles explained the difference in shoot elongation upon submergence. Since this is the exact signal transduction level that also explains the variation in flooding-induced shoot elongation among plant species (namely, R. palustris and Rumex acetosa), we suggest that natural selection results in similar modification of regulatory pathways within and between species.
PHOSPHATIDIC ACID PHOSPHOHYDROLASE1 and 2 Regulate Phospholipid Synthesis at the Endoplasmic Reticulum in Arabidopsis
Authors: Eastmond Peter J. , Quettier Anne-Laure , Kroon Johan T.M. , Craddock Christian , Adams Nicolette , Slabas Antoni R.
Published: August 2010

Phospholipid biosynthesis is essential for the construction of most eukaryotic cell membranes, but how this process is regulated in plants remains poorly understood. Here, we show that in Arabidopsis thaliana, two Mg2+-dependent phosphatidic acid phosphohydrolases called PAH1 and PAH2 act redundantly to repress phospholipid biosynthesis at the endoplasmic reticulum (ER). Leaves from pah1 pah2 double mutants contain ~1.8-fold more phospholipid than the wild type and exhibit gross changes in ER morphology, which are consistent with massive membrane overexpansion. The net rate of incorporation of [methyl-14C]choline into phosphatidylcholine (PC) is ~1.8-fold greater in the double mutant, and the transcript abundance of several key genes that encode enzymes involved in phospholipid synthesis is increased. In particular, we show that PHOSPHORYLETHANOLAMINE N-METHYLTRANSFERASE1 (PEAMT1) is upregulated at the level of transcription in pah1 pah2 leaves. PEAMT catalyzes the first committed step of choline synthesis in Arabidopsis and defines a variant pathway for PC synthesis not found in yeasts or mammals. Our data suggest that PAH1/2 play a regulatory role in phospholipid synthesis that is analogous to that described in Saccharomyces cerevisiae. However, the target enzymes differ, and key components of the signal transduction pathway do not appear to be conserved.
A Model of Rater Behavior in Essay Grading Based on Signal Detection Theory
Authors: DeCarlo Lawrence T.
Published: August 2010

An approach to essay grading based on signal detection theory (SDT) is presented. SDT offers a basis for understanding rater behavior with respect to the scoring of construct responses, in that it provides a theory of psychological processes underlying the raters' behavior. The approach also provides measures of the precision of the raters and the accuracy of classifications. An application of latent class SDT to essay grading is detailed, and similarities to and differences from item response theory (IRT) are noted. The validity and utility of classifications obtained from the SDT model and scores obtained from IRT models are compared. Validity coefficients were found to be about equal in magnitude across SDT and IRT models. Results from a simulation study of a 5‐class SDT model with eight raters are also presented.
The cause of petaloid colouring in ‘Apetalous’ Flowers
Authors: Saunders Edith R.
Published: August 2010

The typical dichlamydeous cyclic Dicotyledon is so organised that the petaloid character of the corolla can be regarded as a function of a certain combination of conditions as regards time and space: time, in so far that the petaloid feature occurs at a definite stage in the series of developmental processes, following, as it does, upon the differentiation of a (usually) uncoloured (i.e. green) calyx; space, in that it is exhibited on the set of radii alternating with the radii of the sepals. Penetrating a little below the surface appearance, we find we can express these same relations in terms of the vascular anatomy as follows. Those floral members (again taking the typical case) which receive as midribs the first set of equidistant bundles to leave the central cylinder show sepaloid characters; those similarly receiving as midrib bundles the outgoing strands on the alternate set of radii exhibit petaloid colouring.

It is found that the marginal veins of the sepals of such Dicotyledon types arise in two different ways, less frequently as true lateral veins from the midribs, more often either through the detachment from the central cylinder on the alternate radii of trunk cords which dissociate in due course into a petal midrib and twin bundles which enter the adjacent side of the sepal to right and left, respectively, and become the marginal vein of that side; or through the departure of pairs of separate strands within the limits of the corresponding alternate sectors.

In typical monochlamydeous cyclic Dicotyledons radial organisation follows the same scheme as in dichlamydeous types, notwithstanding that the perianth here takes the form of a single whorl of structures. Such monochlamydeous types may be divided into two classes. In the one class only the issuing vascular bundles on the corresponding set of radii enter the perianth members. These bundles become the midribs. They may give off lateral veins at any point or may remain unbranched. In either case the individual member is homologous with the individual sepal and is typically green. In the other class each member receives not only the bundle on its own radius but also half the perianth component proper to the alternate radius on each side, either as separate strands or (in gamophyllous types) as undisjoined components of perianth-stamen trunk cords. The first-mentioned bundle becomes the midrib of the tepal, the two others become marginal veins, the one entering the tepal on the right, the other that on the left. In forms belonging to this class the tepals are typically petaloid. Each may be regarded as the counterpart of one sepal of dichlamydeous types + half the neighbouring petal on either side. This equivalence is not infrequently indicated outwardly by the considerable thickness of the tepal members as compared with that of the sepals and petals of the nearest allied dichlamydeous forms.

The accompanying drawings were made by Miss D. F. M. Pertz, to whom I desire to express my grateful thanks.
Upregulation of lipocortin 1 inhibits tumour necrosis factor‐induced apoptosis in human leukaemic cells: a possible mechanism of resistance to immune surveillance
Authors: Wu Yu‐Ling , Jiang Xu‐Rong , Lillington Debra M. , Newland Adrian C. , Kelsey Stephen M.
Published: August 2010

The signal transduction pathway through which tumour necrosis factor (TNF) induces apoptosis in leukaemic cells may involve activation of cytosolic phospholipase A2 (cPLA2). The steroids dexamethasone (Dex) and 1,25(OH)2 D3 both render U937 leukaemic cells resistant to TNF‐induced apoptosis. In this study, we found that Dex inhibited both spontaneous and TNF‐induced activation of cPLA2. Dex had no direct effect on cellular cPLA2 levels, but facilitated cPLA2 degradation upon subsequent stimulation of cells with TNF. In addition, Dex increased synthesis of the endogenous cPLA2 inhibitor lipocortin 1 (LC1). An antisense oligonucleotide to LC1 could completely abrogate Dex‐induced resistance to the cytotoxic action of TNF. Constitutive LC1 levels were relatively higher in myeloid leukaemic blasts showing resistance to TNF than TNF‐sensitive myeloid leukaemic cell lines. Our data suggest that Dex confers the resistance of U937 cells to TNF‐induced apoptosis by upregulating intracellular levels of LC1 and by facilitating a negative‐feedback loop, which is activated upon stimulation with TNF. High constitutive levels of LC1 in leukaemic blasts may protect them against immune‐mediated killing.
Insecticide‐treated bednets reduce mortality and severe morbidity from malaria among children on the Kenyan coast
Authors: Nevill C. G. , Some E. S. , Mung'ala V. O. , Muterni W. , New L. , Marsh K. , Lengeler C. , Snow R. W.
Published: August 2010

New tools to prevent malaria morbidity and mortality are needed to improve child survival in sub‐Saharan Africa. Insecticide treated bednets (ITBN) have been shown, in one setting (The Gambia, West Africa), to reduce childhood mortality. To assess the impact of ITBN on child survival under different epidemiological and cultural conditions we conducted a community randomized, controlled trial of permethrin treated bednets (0.5 g/m2) among a rural population on the Kenyan Coast.

Between 1991 and 1993 continuous community‐based demographic surveillance linked to hospital‐based in‐patient surveillance identified all mortality and severe malaria morbidity events during a 2‐year period among a population of over 11 000 children under 5 years of age. In July 1993, 28 randomly selected communities were issued ITBN, instructed in their use and the nets re‐impregnated every 6 months. The remaining 28 communities served as contemporaneous controls for the following 2 years, during which continuous demographic and hospital surveillance was maintained until the end of July 1995.

The introduction of ITBN led to significant reductions in childhood mortality (PE 33%, CI 7–51%) and severe, life‐threatening malaria among children aged 1–59 months (PE 44%, CI 19–62). These findings confirm the value of ITBN in improving child survival and provide the first evidence of their specific role in reducing severe morbidity from malaria.
Health seeking behaviour for child illness in rural Guatemala
Authors: van der Stuyft Patrick , Sorensen Soren C. , Delgado Eugenia , Bocaletti Elizabeth
Published: August 2010

Considerable efforts were made in Guatemala to cover rural areas with health centres, and health programmes have been launched to treat and prevent the most important childhood diseases. Despite this, the utilization rate of public health services has reportedly been low throughout the past two decades. How, and how effectively, do mothers resolve the health problems of their children? To gain better insight into health care behaviour, we conducted a health services utilization survey in two highland communities in the department of Sacatepequez in 1992–1993.

We asked 324 mothers in two villages whether, and where, they had sought help the last time their children under 5 years of age had suffered from diarrhoea, fever, cough symptoms or worms. Mothers relied on home care in 63–83% of reported episodes and the use of health services—Western or traditional—was consistently low. Although Western health care was easily accessible, it was used in only 8–15% of cases. The only identifiable significant independent determinants of utilization were occupational status of the mother (RR=1.5 if employed) and overall level of socioeconomic development of the community (RR=1.7).

Inquiry into treatments used revealed that except for worms, which were frequently treated with herbs (31%) or external remedies (20%) alone, modern pharmaceuticals predominated. Antibiotics were the remedy of choice against diarrhoea (63%), antipyretics in case of fever (83%) and cough syrups with expectorants or antitussives against cough (65%). One hundred and twenty‐one of the children born after 1975 died; in only 64 cases (53%) was a Western health service consulted between onset of disease and death.

No relation was found between attendance and socioeconomic characteristics of the parents, but a positive linear association between duration of the fatal illness episode and age of the child could be identified. Independent sources report a drop in infant mortality of 53 and 35% respectively in the two communities between 1977 and 1991. Our findings seem to indicate that this reduction was achieved despite under‐utilization of Western health services.
Recent developments in hygiene behaviour research: an emphasis on methods and meaning
Authors: Almedom Astier M.
Published: August 2010

This paper discusses some of the recent developments in hygiene behaviour research, focusing on operational research. A series of ‘rapid’ assessments of hygiene behaviour were carried out in Kenya, Tanzania and Ethiopia with a view to preparing a field handbook entitled Hygiene Evaluation Procedures (HEP). The HEP handbook is intended primarily for field personnel in water supply, sanitation and health/hygiene education projects who want to design and conduct their own systematic assessments of hygiene behaviour in their localities. The short studies provided useful practical insights into the concerns and needs of project staff for whom research allowances (human, material and time resources) are often very limited. In this paper emphasis is placed on both methodological and heuristic developments as the two are inseparable. It is suggested that in the domestic sphere, hygiene behaviour with respect to the disposal of children's faeces and domestic water use are two of the key areas that remain of universal relevance to water/sanitation related interventions. These can be assessed rapidly and effectively by using two indicators: means of disposal of children's faeces and handwashing at ‘critical’ times—after defaecation, after handling and/or disposing of children's faeces, before handling food and before feeding young children and eating. Appropriate combinations of anthropological methods and participatory tools for measuring these indicators are described. The practical relevance of the resulting data for project design and implementation is highlighted.
Pathogenetic factors of acute schistosomiasis mansoni: correlation of worm burden, IgE, blood eosinophilia and intensity of clinical manifestations
Authors: Rocha M. O. C. , Pedroso E. R. P. , Greco D. B. , Lambertucci J. R. , Katz N. , Rocha R. L. , Rocha R. S. , Rezende D. F. , Neves J.
Published: August 2010

A clinical study of 34 previously healthy young patients simultaneously infected in an endemic area of schistosomiasis mansoni is presented, emphasizing the initial phase of the infection. Its intensity was established according to the occurrence, intensity, and duration of the signs and symptoms in order to investigate the possible correlations between the worm burden (estimated by the number of eggs in faeces), the blood eosinophilia and specific levels of IgE (estimated by the area of immediate intradermal reaction), with the clinical manifestations. A significant but low‐level association was found between the worm burden and morbidity, suggesting that multiple factors, besides worm burden itself, may contribute to the pathogenesis of the disease.
Leishmania tropica in Egypt: an undesirable import
Authors: Mohareb Emad W. , Mikhail Elen M. , Youssef Fouad G.
Published: August 2010

Cutaneous as well as visceral leishmaniasis has been previously reported in Egypt. The former clinical manifestation is attributed to Leishmania major, the latter to L. infantum. In this study, L. tropica was isolated from an Egyptian labourer returning from Saudi Arabia. Amastigotes were detected by both Giemsa staining and indirect immunofluorescence using rabbit anti‐gp63. Promastigotes from Schneider's medium were typed isoenzymatically as L. tropica. In view of the emerging threat of visceralization of L. tropica, the potential risk for its transmission in Egypt is discussed.
Treatment practices for degedege, a locally recognized febrile illness, and implications for strategies to decrease mortality from severe malaria in Bagamoyo District, Tanzania
Authors: Makemba A. M. , Winch P. J. , Makame V. M. , Mehl G. L. , Premji Z. , Minjas J. N. , Sniff C. J.
Published: August 2010

Malaria remains one of the chief causes of mortality among young children in sub‐Saharan Africa. Verbal autopsies for cases of childhood mortality in Bagamoyo District, Tanzania demonstrated that degedege, a locally defined illness of children characterized by fever and convulsions, is frequently treated by traditional healers. To investigate this further, an ethnographic study was carried out in one village that included in‐depth interviews with 14 traditional healers and 3 focus groups with parents. Parents and traditional healers were unanimous in their conviction that degedege requires traditional treatments, at least initially, and that these treatments are effective. While traditional healers do refer cases that are not improving to the District Hospital, this frequently occurs late in the course of the illness, after one or more stages of traditional treatments. The prognosis will thus be poor for those children who are suffering from severe malaria. Consideration should be given to enlisting the support of traditional healers in efforts to improve treatment for severe malaria, including teaching them how to distinguish febrile convulsions from cases of severe malaria.
Viability and fertility of adult Onchocerca volvulus after 6 years of treatment with ivermectin
Authors: Kläger S. L. , Whitworth J. A. G. , Downham M. D.
Published: August 2010

Onchocerca volvulus nodules were removed from 77 fully compliant patients in a longitudinal study of ivermectin treatment in Sierra Leone. The patients had participated in a randomized controlled trial and received either 4 annual doses of ivermectin or 10 6‐monthly doses over 6 years. Worms were examined 9 months after the last treatment for evidence of changes in morphology, viability and reproductivity. The findings were compared with results for the 2 groups obtained at earlier surveys of the same study population. Repeated treatment at 6 and 12‐month intervals has resulted in a marked ageing of the male worm population profile and a significant reduction in the proportion of live female worms found in the nodules. In addition, there has been a reduction in reproductivity of 90% or more. However, most of the worms found were still alive and potentially fertile, underlining the need for the continuation of regular ivermectin treatment to maintain the benefits achieved.
Response of childhood malaria to chloroquine and Fansidar in an area of intermediate chloroquine resistance in Côte d'Ivoire
Authors: Henry M.‐C. , Eggelte T. A. , Watson P. , van Leeuwen B. Docters , Bakker D. A. , Kluin J.
Published: August 2010

The parasitological, clinical and haematological responses to chloroquine treatment were studied in children during a 28‐day follow‐up in an area of Côte d'Ivoire with intermediate chloroquine resistance. The parasitological, clinical and haematological responses to Fansidar were also investigated in patients who returned to the health centre within 28 days with symptoms of malaria. Of 82 children aged 0–9 years who completed the study, only 67% were parasite‐negative on thick blood film on day 7, which decreased to 21% by day 28. While chloroquine treatment still produced clinical remission at day 7 in 95% of the children, 35% had recurrent fever with concomitant parasitaemia before day 28. All fever cases subsequently treated with Fansidar remained parasite‐negative over a period of 28 days. On day 28 the haematocrit levels were higher in those children who responded successfully to treatment with either chloroquine or Fansidar than in the children who were still parasite‐positive but without fever (two‐tailed t‐test, P=0.02). The rate of resistance to chloroquine was most pronounced among the younger children (< 5 years), 18% of whom showed clinical failure by day 14. This study underlines the importance of monitoring the durability of response to chloroquine treatment for at least 14 days in young children in Côte d'Ivoire.
Evaluation of IgG4 response in ascariasis by ELISA for serodiagnosis
Authors: Chatterjee B. P. , Santra A. , Karmakar P. Roy , Mazumder D. N. Guha
Published: August 2010

The excretory/secretory (ES) antigen(s) of Ascaris lumbricoides was fractionated into 10 fractions by gel chromatography on a Suparose 12 column in FPLC. Of these, the third fraction (Al III), showing binding activity with both IgE and IgG antibodies of A. lumbricoides infected patients' sera, was further resolved into 2 fractions (Al IIIa and Al IIIb) on passage through a Mono Q column. Al IIIb was found to be the most potent antigen due to its high binding affinity with IgE and IgG antibodies of Ascaris infected patients as evidenced by ELISA inhibition. Although a two to five‐fold increase of serum IgE level was observed in all helminthic parasite infected patients studied compared to control subjects, Al IIIb specific IgE was detected in sera of all Ascaris infected and only 40% of hookworm infected patients. When Al IIIb was tested by ELISA with sera of control subjects, Ascaris, hookworm, Strongyloides and Trichuris infected patients, strong binding was observed with the IgE and also IgG of all the Ascaris infected patients; however, it cross‐reacted with IgG in 50% of hookworm, 28.6% of Trichuris trichura and 22.2% of Strongyloides infected patients' sera; but with IgE only in 40% of hookworm infected patients' sera. Further study showed specific detection of IgG4 in all the serum samples of 65 Ascaris infected patients when Al IIIb antigen was allowed to react with different subclasses of IgG by ELISA, giving a sensitivity of 100%. Reactivities of Al IIIb with IgG1, and IgG3, were only 47.6 and 11.8% respectively and there was no reactivity with IgG2, subclass. No IgG4 reactivity against Al IIIb was observed in the sera of hookworm, Trichuris or Strongyloides infected patients and was similar to that observed with control subjects showing the 100% specificity of the test system. This study may therefore be regarded as a novel technique for serodiagnosis of ascariasis by measuring Ascaris specific IgG4.
Ascaris suum: molecular cloning of an intermediate filament*
Authors: Bisoffi Marco , Betschart Bruno
Published: August 2010

It has been proposed that intermediate filament proteins are involved in force transduction from the muscle cells through the hypodermis to the cuticle of nematodes. An additional role of intermediate filaments as excretory/secretory components of parasitic nematodes is under discussion. We report on the molecular characterization of the cDNA clone AsIF of the intestinal nematode parasite Ascaris suum, encoding a member of the intermediate filament protein family by sequence comparison with intermediate filaments of other nematodes. We also show the precise location of the product encoded by AsIF within the organism by immunoelectron microscopy.
Community‐based investigation of an outbreak of acute viral conjunctivitis in urban slums
Authors: Nayak N. , Gupta Sanjeev K. , Murthy G. V. S. , Satpathy G. , Mohanty S.
Published: August 2010

Nine hundred and sixteen people from 143 randomly selected households were included in this community‐based investigation of an outbreak of acute viral conjunctivitis in urban slum communities of Delhi in 1994. During the 2‐weeks recall period, 456 (49.8%) had conjunctivitis and 229 (25%) were symptomatic at the time of this investigation. Overall, females had a higher attack rate than males (P<0.05). The attack rate increased with age (P<0.001). A total of 61.6% of the conjunctival swabs were antigen positive as evidenced by indirect immunofluorescence assay. Viruses could be isolated from 30.3% of the samples processed. Out of these, 70% were identified as Coxsackie A 24 and 30% as EV 70.
Resistance of Blastocystis hominis cysts to metronidazole
Authors: Zaman V. , Zaki M.
Published: August 2010

Blastocystis hominis cysts concentrated from faeces were resistant to metronidazole up to a concentration of 5 mg/ml. A cysticidal drug is therefore needed for radical treatment, to avoid relapse and to prevent transmission.
The study of hygiene behaviour in Botswana: a combination of qualitative and quantitative methods
Authors: Kaltenthaler E. C. , Drašar B. S.
Published: August 2010

This paper describes a study from northern Botswana which explored the relationship between hygiene behaviour and diarrhoeal diseases in young children. Both qualitative and quantitative data collection methods were used. The qualitative methods included observations, key informant interviews, in‐depth interviews and focus groups. The quantitative methods included spot check observations, anthropometric measurements, the monitoring of diarrhoea morbidity and the administration of a socioeconomic questionnaire. A profile of hygiene behaviours was developed for this community and traditional beliefs related to diarrhoea were identified. The methods described provided considerable information in a short period of time. They were also relatively inexpensive and easy to implement, thus providing a model for further studies dealing with hygiene behaviour in developing countries. The information gathered enabled the identification of areas needing further research, the development of health education programmes and provided the basis for larger epidemiological studies.