bluuebunny/crossref_metadata_2025 huggingface dataset:
Chromosome territory reorganization in a human disease with altered DNA methylation
Authors: Matarazzo Maria R. , Boyle Shelagh , D'Esposito Maurizio , Bickmore Wendy A.
Published: October 2007

Chromosome territory (CT) organization and chromatin condensation have been linked to gene expression. Although individual genes can be transcribed from inside CTs, some regions that have constitutively high expression or are coordinately activated loop out from CTs and decondense. The relationship between epigenetic marks, such as DNA methylation, and higher-order chromatin structures is largely unexplored.
DNMT3B
mutations in immunodeficiency centromeric instability facial anomalies (ICF) syndrome result in loss of DNA methylation at particular sites, including CpG islands on the inactive X chromosome (Xi). This allows the specific effects of DNA methylation on CTs to be examined. Using fluorescence
in situ
hybridization, we reveal a differential organization of the human pseudoautosomal region (PAR)2 between the CTs of the X and Y in normal males and the active X (Xa) and the Xi in females. There is also a more condensed chromatin structure on Xi compared with Xa in this region. PAR2 genes are relocalized toward the outside of the Y and Xi CTs in ICF, and on the Xi, we show that this can extend to genes distant from the site of DNA hypomethylation itself. This reorganization is not simply a reflection of the transcriptional activation of the relocalized genes. This report of altered CT organization in a human genetic disease illustrates that DNA hypomethylation at restricted sites in the genome can lead to more extensive changes in nuclear organization away from the original site of epigenetic change.
Cross-presentation of glycolipid from tumor cells loaded with α-galactosylceramide leads to potent and long-lived T cell–mediated immunity via dendritic cells
Authors: Shimizu Kanako , Kurosawa Yuri , Taniguchi Masaru , Steinman Ralph M. , Fujii Shin-ichiro
Published: October 2007

We report a mechanism to induce combined and long-lived CD4+ and CD8+ T cell immunity to several mouse tumors. Surprisingly, the initial source of antigen is a single low dose of tumor cells loaded with α-galactosylceramide (α-GalCer) glycolipid (tumor/Gal) but lacking co-stimulatory molecules. After tumor/Gal injection intravenously (i.v.), innate NKT and NK cells reject the tumor cells, some of which are taken up by dendritic cells (DCs). The DCs in turn cross-present glycolipid on CD1d molecules to NKT cells and undergo maturation. For B16 melanoma cells loaded with α-GalCer (B16/Gal), interferon γ–producing CD8+ T cells develop toward several melanoma peptides, again after a single low i.v. dose of B16/Gal. In all four poorly immunogenic tumors tested, a single dose of tumor/Gal i.v. allows mice to become resistant to tumors given subcutaneously. Resistance requires CD4+ and CD8+ cells, as well as DCs, and persists for 6–12 mo. Therefore, several immunogenic features of DCs are engaged by the CD1d-mediated cross-presentation of glycolipid-loaded tumor cells, leading to particularly strong and long-lived adaptive immunity.
TAP-1 indirectly regulates CD4+ T cell priming in Toxoplasma gondii infection by controlling NK cell IFN-γ production
Authors: Goldszmid Romina S. , Bafica Andre , Jankovic Dragana , Feng Carl G. , Caspar Pat , Winkler-Pickett Robin , Trinchieri Giorgio , Sher Alan
Published: October 2007

To investigate if transporter associated with antigen processing (TAP)–1 is required for CD8+ T cell–mediated control of Toxoplasma gondii in vivo, we compared the resistance of TAP-1−/−, CD8−/−, and wild-type (WT) mice to infection with the parasite. Unexpectedly, TAP-1−/− mice displayed greater susceptibility than CD8−/−, β2-microglobulin−/− (β2m−/−), or WT mice to infection with an avirulent parasite strain. The decreased resistance of the TAP-1−/− mice correlated with a reduction in the frequency of activated (CD62Llow CD44hi) and interferon (IFN)-γ–producing CD4+ T cells. Interestingly, infected TAP-1−/− mice also showed reduced numbers of IFN-γ–producing natural killer (NK) cells relative to WT, CD8−/−, or β2m−/− mice, and after NK cell depletion both CD8−/− and WT mice succumbed to infection with the same kinetics as TAP-1−/− animals and displayed impaired CD4+ T cell IFN-γ responses. Moreover, adoptive transfer of NK cells obtained from IFN-γ+/+, but not IFN-γ−/−, animals restored the CD4+ T cell response of infected TAP-1−/− mice to normal levels. These results reveal a role for TAP-1 in the induction of IFN-γ–producing NK cells and demonstrate that NK cell licensing can influence host resistance to infection through its effect on cytokine production in addition to its role in cytotoxicity.
Development and function of murine B220+CD11c+NK1.1+ cells identify them as a subset of NK cells
Authors: Blasius Amanda L. , Barchet Winfried , Cella Marina , Colonna Marco
Published: October 2007

Lymphoid organs contain a B220+CD11c+NK1.1+ cell population that was recently characterized as a novel dendritic cell (DC) subset that functionally overlaps with natural killer (NK) cells and plasmacytoid DCs (PDCs). Using Siglec-H and NK1.1 markers, we unambiguously dissected B220+CD11c+ cells and found that PDCs are the only professional interferon (IFN)-α–producing cells within this heterogeneous population. In contrast, B220+CD11c+NK1.1+ cells are a discrete NK cell subset capable of producing higher levels of IFN-γ than conventional NK cells. Unlike DCs, only a minute fraction of B220+CD11c+NK1.1+ cells in the spleen expressed major histocompatibility complex class II ex vivo or after stimulation with CpG. Consistent with being a NK cell subset, B220+CD11c+NK1.1+ cells depended primarily on interleukin 15 and common cytokine receptor γ chain signaling for their development. In terms of function, expression of distinctive cell surface receptors, and location in lymphoid organs, NK1.1+B220+CD11c+ appear to be the murine equivalent of human CD56bright NK cells.
Leveraging the structure of the Semantic Web to enhance information retrieval for proteomics
Authors: Smith Andrew , Cheung Kei , Krauthammer Michael , Schultz Martin , Gerstein Mark
Published: October 2007

Motivation: Proteomics researchers need to be able to quickly retrieve relevant information from the web and the biomedical literature. To improve information retrieval, we leverage the structure of the semantic web, developing an approach for joining it with the largely opposing paradigm of unsupervised web search.

Results: Our approach uses a Resource-Description-Framework (RDF) graph that inter-relates documents through their associated biological identifiers (e.g., protein ID). A search begins with a simple query term (UniProt identifier), which is expanded with terms extracted from documents in the RDF graph surrounding the query (“the subgraph”). We re-rank documents in the full corpus (e.g. all PubMed) by their cosine-similarity scores against a composite word-weight vector created from the subgraph. This vector is a weighted sum of individual word-weight vectors for documents at each node of the subgraph, taking into account the types of relationships between the central query identifier and the nodes connected to it. The computation also uses inverse document frequency (IDF) in a novel way to rescale the local word frequencies in the query's subgraph relative to that in other subgraphs. Applying our procedure to PubMed, we optimize weights for various relationships in the subgraph and benchmark overall performance in detail. Using a subgraph containing family relationships (from PFAM) results in a significant improvement in accuracy (as compared to not considering the subgraph in the search) when assessed against known relationships in the yeast literature. Moreover, we achieve this accuracy using only relatively simple and computationally efficient methods.

Contact:  mark.gerstein@yale.edu

Supplementary information:  http://hub.gersteinlab.org/ir-supp/
Three New Races of the Spinach Downy Mildew Pathogen Identified by a Modified Set of Spinach Differentials
Authors: Irish B. M. , Correll J. C. , Koike S. T. , Morelock T. E.
Published: October 2007

Spinach downy mildew, caused by Peronospora farinosa f. sp. spinaciae, is the most economically important disease of spinach worldwide. During the past few years, spinach cultivars resistant to the seven previously described races of P. farinosa f. sp. spinaciae were observed to be severely affected by downy mildew in both the United States and the European Union. Four new isolates of P. farinosa f. sp. spinaciae were collected from California and The Netherlands and characterized based on disease reactions on two modified sets of spinach differentials. The results led to the description of three new races of the downy mildew pathogen, designated races 8, 9, and 10. Four differential cultivars with resistance to races 1 to 7 were used to distinguish the three new races. Dolphin was susceptible to races 8 and 10 but resistant to race 9; Lion was susceptible to race 10 but resistant to races 8 and 9; Lazio was resistant to races 1 to 7 as well as races 8, 9, and 10; and Tarpy was susceptible to all three new races. The three new races also were used to evaluate the disease reactions on 43 contemporary commercial spinach cultivars in greenhouse trials. A survey of 58 isolates of P. farinosa f. sp. spinaciae collected in California and Arizona between 2004 and 2006 revealed that race 10 predominated in the areas sampled.
Severity of Curvularia Stem Blight Disease of Cassava in West Africa
Authors: Msikita W. , Baimey H. , James B. D.
Published: October 2007

In diagnostic surveys, Curvularia stem blight affected 9, 13, and 38% of cassava fields, respectively, in Benin, Ghana, and Nigeria. Disease incidence (number of plants with visible symptoms per total sampled) ranged between 0 and 80%, and severity (number of lesions) between 2 and 25 lesions per stem. In greenhouse studies, the fungus inhibited shoot growth depending on the degree of bud colonization, such that when buds were completely colonized, they failed to sprout. Partially colonized buds sprouted, but depending on genotype, overall growth was reduced 20 to 50% compared with healthy stems. Shoot growth for all artificially inoculated cultivars was consistently lower than for the respective noninoculated plants, and they suffered up to 50% leaf abscission. In two field localities, shoot sprouting for cultivars TMS 30572 and Odongbo was reduced 4 to 18% and 26 to 58% compared with noninoculated stems.
A Site-Specific, Weather-Based Disease Regression Model for Sclerotinia Blight of Peanut
Authors: Smith D. L. , Hollowell J. E. , Isleib T. G. , Shew B. B.
Published: October 2007

In North Carolina, losses due to Sclerotinia blight of peanut, caused by the fungus Sclerotinia minor, are an estimated 1 to 4 million dollars annually. In general, peanut (Arachis hypogaea) is very susceptible to Sclerotinia blight, but some partially resistant virginia-type cultivars are available. Up to three fungicide applications per season are necessary to maintain a healthy crop in years highly favorable for disease development. Improved prediction of epidemic initiation and identification of periods when fungicides are not required would increase fungicide efficiency and reduce production costs on resistant and susceptible cultivars. A Sclerotinia blight disease model was developed using regression strategies in an effort to describe the relationships between modeled environmental variables and disease increase. Changes in incremental disease incidence (% of newly infected plants of the total plant population per plot) for the 2002–2005 growing seasons were statistically transformed and described using 5-day moving averages of modeled site-specific weather variables (localized, mathematical estimations of weather data derived at a remote location) obtained from SkyBit (ZedX, Inc.). Variables in the regression to describe the Sclerotinia blight disease index included: mean relative humidity (linear and quadratic), mean soil temperature (quadratic), maximum air temperature (linear and quadratic), maximum relative humidity (linear and quadratic), minimum air temperature (linear and quadratic), minimum relative humidity (linear and quadratic), and minimum soil temperature (linear and quadratic). The model explained approximately 50% of the variability in Sclerotinia blight index over 4 years of field research in eight environments. The relationships between weather variables and Sclerotinia blight index were independent of host partial resistance. Linear regression models were used to describe progress of Sclerotinia blight on cultivars and breeding lines with varying levels of partial resistance. Resistance affected the rate of disease progress, but not disease onset. The results of this study will be used to develop site- and cultivar-specific spray advisories for Sclerotinia blight.
Reduction in Common Rust Severity Conferred by the Rp1D Gene in Sweet Corn Hybrids Infected by Mixtures of Rp1D-Virulent and Avirulent Puccinia sorghi
Authors: Pataky Jerald K. , Campaña M. Andrea
Published: October 2007

The Rp1D gene confers a hypersensitive, chlorotic-fleck, resistant reaction to Puccinia sorghi, the casual agent of common rust of corn. About 40% of commercial sweet corn hybrids carry the Rp1D gene. Sine 1999, Rp1D-virulent (D-virulent) isolates of P. sorghi have occurred regularly in populations of P. sorghi in North America. Observations from sweet corn hybrid nurseries and other trials indicate that the frequency of D-virulent isolates affects severity of rust on Rp1D hybrids; however, the frequency of D-virulence at which the Rp1D gene is rendered completely ineffective is not known. The objective of this study was to assess whether common rust severity is reduced by the Rp1D gene in sweet corn hybrids infected by mixtures of D-virulent and Rp1D-avirulent (avirulent) P. sorghi. Forty pairs of Rp1D-resistant and susceptible (rp1d) versions of sweet corn hybrids from six different commercial breeding programs were evaluated in 2003 and 2004 in trials inoculated with one of five different ratios of avirulent:D-virulent inocula: 100:0, 90:10, 80:20, 60:40, or 0:100. When D-virulent P. sorghi was 100% of initial inoculum, common rust was equally severe on Rp1D and rp1d versions of the same hybrid. Thus, the Rp1D gene did not confer partial or residual resistance in these trials. When initial inocula consisted of 40% or less D-virulent P. sorghi, rust was significantly less severe on Rp1D versions than on rp1d versions of the same hybrids. Relationships between rust severity on Rp1D and rp1d versions of hybrids were explained by linear regressions in all trials. Slope coefficients (i.e., rust severity on Rp1D hybrids as a proportion of that on rp1d hybrids) were related to the percentage of D-virulent P. sorghi in the initial inoculum and were 0.21, 0.29, 0.51, 0.64, and 0.93 in 2003 and 0.25, 0.50, 0.67, 0.76, and 1.0 in 2004 for trials inoculated with 0, 10, 20, 40, and 100% D-virulent P. sorghi, respectively. Thus, the Rp1D gene may convey levels of control in proportion to the frequency of virulence in mixed populations of D-virulent and avirulent P. sorghi when the frequency of virulent isolates is less than 40%.
Detection of Flavescence Dorée Phytoplasma in Grapevine by Reverse-Transcription PCR
Authors: Margaria P. , Rosa C. , Marzachì C. , Turina M. , Palmano S.
Published: October 2007

Flavescence dorée (FD) is the most serious phytoplasma disease of grapevine. This report describes a novel method of detecting FD phytoplasma based on reverse-transcription polymerase chain reaction (RT-PCR) on 16S ribosomal RNA (16SrRNA) which will greatly improve mass screening of infected grapevines. A rapid protocol for extracting sap from whole leaves or midveins and successive one-tube amplification by RT-PCR was applied to grapevine samples with or without symptoms collected from different areas of Piedmont (northwestern Italy). Results were compared with those obtained using one of the current diagnostic methods that utilizes nested PCR on phytoplasma DNA-enriched preparations. A Cohen's kappa index of 0.76 indicated a substantial agreement between the two sets of results. The RT-PCR method has the advantage of being a rapid, reliable, and sensitive assay for large-scale screening of grapevines.
Impatiens necrotic spot virus and Tomato spotted wilt virus Diagnosed in Phalaenopsis Orchids from Two Florida Nurseries
Authors: Baker C. A. , Davison D. , Jones L.
Published: October 2007

In October 2006 (Arcadia, FL) and January 2007 (Sorrento, FL), several white Phalaenopsis orchids with large chlorotic/necrotic ringspot symptoms were sent to the Division of Plant Industry, Gainesville, FL. Symptomatic leaf tissues were tested with the Agdia immunostick-comb (Agdia, Elkhart, IN) for Impatiens necrotic spot virus (INSV), Tomato spotted wilt virus (TSWV), Cucumber mosaic, and Tobacco mosaic virus. Plants from the nursery in Sorrento, FL tested positive for TSWV, while those from the nursery in Arcadia, FL tested positive for INSV. Symptomless leaves from the infected plants tested negative for the viruses with the immunostick-comb. The plants also were tested for TSWV and INSV by double-antibody (DAS)-ELISA (Agdia Inc.) with the same results. Total RNA was extracted from one symptomatic orchid leaf from each nursery. Reverse transcription (RT)-PCR was performed with the universal tospovirus primer set BR60and BR65 (1). PCR bands of the expected size were amplified from each leaf. PCR products were sequenced directly. The orchid leaf that tested positive for TSWV by ELISA produced a 495-bp sequence with 97% identity to several isolates of the TSWV nucleocapsid protein gene listed in GenBank (Accession Nos. AY744479, AY8770391, DQ376185, and AF02659). The orchid leaf that tested positive for INSV by ELISA produced a 396-bp sequence with 98 to 99% identity to several isolates of the INSV nucleocapsid protein gene (Accession Nos. D00914, DQ425096, X66972, and AD109100). Although these viruses have been reported a few times in orchids previously (2,3), to our knowledge, this is the first time they have been reported in this host in Florida. In addition, white Phalaenopsis spp. appears to be a local lesion host and not a systemic host for these viruses.

References: (1) M. Eiras et al. Fitopatol. Bras. 26:170, 2001. (2) J. S. Hu et al. Plant Dis. 77:464, 1993. (3) S. T. Koike and D. E. Mayhew. Orchids 70:746, 2001.
First Report of Leaf Spot and Root Rot Caused by Phoma betae on Beta vulgaris subsp. vulgaris (Garden Beet Group) in Italy
Authors: Garibaldi A. , Gilardi G. , Bertetti D. , Gullino M. L.
Published: October 2007

In the winter of 2007 in Piedmont (northern Italy), symptoms of a previously unknown disease were observed on beet (Beta vulgaris L. subsp. vulgaris) (garden beet group) grown under a tunnel on several commercial farms near Cuneo. First symptoms appeared on 1-month-old plants, occurring as brown, round-to-oval spots as much as 2 cm in diameter with dark concentric rings near the perimeter. Small, dark pycnidia were present throughout the spots in concentric rings. Generally, older, lower leaves were affected more than the younger ones. Ten to fifteen percent of the plants were affected. Symptoms on the roots began near the crown as small, dark, sunken spots that became soft and water soaked. Eventually, spots on the roots turned dark brown to black and black lines separated diseased and healthy tissues. Older infected tissues were black, dry, shrunken, and spongy. Pycnidia were not observed on affected roots. From infected leaves and roots, a fungus was consistently isolated on potato dextrose agar (PDA) amended with 25 mg/l of streptomycin. The fungus was grown on PDA and maintained at 22°C (12 h of light, 12 h of dark). After 10 days, black pycnidia (130 to 328 [204] μm in diameter) developed, releasing abundant hyaline, elliptical, nonseptate conidia measuring 3.9 to 6.7 (5.1) × 2.4 to 5.9 (3.6) μm. On the basis of its morphological characteristics, the fungus was identified as a Phoma sp. (1). The internal transcribed spacer (ITS) region was amplified using primers ITS4/ITS6 (2) and sequenced. BLASTn analysis of the 557 bp obtained showed an E-value of 0.0 with Phoma betae. The nucleotide sequence has been assigned GenBank Accession No. EU003450. Pathogenicity tests were performed by spraying leaves of healthy 20-day-old potted B. vulgaris plants with a spore and mycelial suspension (1 × 106 spores or mycelial fragments per ml). Noninoculated plants sprayed only with water served as controls. Fifteen plants (three per pot) were used for each treatment. Plants were covered with plastic bags for 5 days after inoculation and kept in a growth chamber at 20°C. Symptoms previously described developed on leaves of all inoculated plants 5 days after inoculation, while control plants remained healthy. Later, pycnidia and conidia, with the same dimensions and characteristics previously described, were observed on the infected leaves. The fungus was consistently reisolated from the lesions of the inoculated plants. The pathogenicity test was carried out twice. P. betae on B. vulgaris var. cycla has been reported in Canada (3) as well as in other countries. The same pathogen was reported in Italy on sugar beet (2).

References: (1) G. H. Boerema and G. J. Bollen. Persoonia 8:111, 1975. (2) A. Canova. Inf. Fitopatol. 16:207, 1966. (3) D. E L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (4) J. R. Howard et al. Diseases of Vegetable Crops in Canada. Canadian Phytopathological Society, 1994.
First Report of Cucumber mosaic virus in Echium candicans in France
Authors: Cardin L. , Moury B.
Published: October 2007

Echium candicans (Linn.) Herb. Banks (Pride of Madeira or Viper's Bugloss), family Boraginaceae, is a perennial shrub used in gardens for the ornamental quality of its deep blue inflorescences, especially in coastal areas near the Mediterranean Sea. Mosaic symptoms were observed in leaves of E. candicans in the Alpes Maritimes Department of southeastern France, St Jean Cap Ferrat in 1994, Menton in 2002, and Antibes in 2005. Symptoms exhibited in a range of inoculated plants including Nicotiana tabacum cvs. Xanthi and Samsun, Chenopodium quinoa, C. amaranticolor, Vigna unguiculata cv. Black, and Cucumis sativus cv. Poinsett were typical of Cucumber mosaic virus (CMV). Occurrence of CMV in one sample from each of the three localities was confirmed by the observation of isometric particles (approximately 30 nm) with the electron microscope in crude sap preparations from the infected plants, positive reactions in double-antibody sandwich (DAS)-ELISA to polyclonal antibodies raised against CMV (1), and the nonpersistent transmission of the virus from infected Xanthi to virus-free Xanthi plants by Myzus persicae. In double-immunodiffusion analysis, the three isolates were shown to belong to the CMV subgroup II (1,2). To determine if CMV was responsible for the symptoms observed, the isolate from Antibes was multiplied in Xanthi plants after isolation from local lesions on V. unguiculata and mechanically inoculated to 3-year-old plants of E. candicans tested to be free from CMV before the mechanical inoculation. One month after inoculation, mild mosaic symptoms were observed in young leaves and CMV was detected by DAS-ELISA in 10 of 10 inoculated plants. To our knowledge, this is the first report of CMV in E. candicans.

References: (1) J.-C. Devergne and L. Cardin. Ann. Phytopathol. 7:225, 1975. (2) M. J. Roossinck. J. Virol. 76:3382, 2002.
Momordica charantia is a Weed Host Reservoir for Papaya ringspot virus Type P in Jamaica
Authors: Chin M. , Ahmad M. H. , Tennant P.
Published: October 2007

Papaya rinsgpot virus type P (PRSV), a member of the genus Potyvirus in the family Potyviridae, is primarily transmitted by aphids in a nonpersistent manner (2). The virus is geographically widespread but has a narrow host range within the plant families Caricaceae, Chenopodiaceae, and Cucurbitaceae (2). The first reported epidemic of PRSV in Jamaica was during the late 1980s (1). Since then, the virus has spread across the island and is recognized as a potential problem for continued production of papaya (Carica papaya L.). In the summers of 1999 and 2000, prominent vein clearing symptoms were observed on leaves of a common weed, cerasee (Momordica charantia L.), in papaya orchards of western Jamaica. This weed, a climbing annual in the Cucurbitaceae family used in a variety of local herbal preparations, was found to be growing on fences or the ground along the periphery of the orchards. Leaf samples were collected and tested for PRSV by double-antibody sandwich (DAS)-ELISA with polyclonal antibodies (Agdia Inc, Elkhart, IN). In addition, crude sap extracts from 12 cerasee leaf samples that were diluted 1:20 were mechanically inoculated onto six plants each of cerasee and papaya. Within 2 weeks, vein clearing symptoms were observed on cerasee and symptoms (vein clearing followed by mosaic development and leaf distortions) typical of PRSV infection were obtained on papaya (2). All original leaf samples and inoculated plants tested positive in DAS-ELISA. In subsequent vector transmission tests, 10 healthy cerasee or papaya seedlings were inoculated with aphids (Aphis gossypii) that were previously permitted to feed on PRSV-infected papaya or cerasee. High rates of virus transmission were achieved in three tests from cerasee to papaya (77 to 83%), papaya to cerasee (90 to 93%), and cerasee to cerasee (60 to 70%). Total RNA from papaya samples was subjected to reverse transcriptase-PCR using primers to the capsid protein gene (3). A single fragment of the expected size (approximately 996 bp) was amplified and sequenced and showed high nucleotide identity (90.3 to 91.4%) with previously reported PRSV type P from Jamaica (GenBank Accession No. DQ104823), Cuba (GenBank Accession No. DQ089482), Florida (GenBank Accession No. AF196839), Brazil (GenBank Accession No. AF344650), and Hawaii (GenBank Accession No. S46722). To our knowledge, this is the first report of the natural occurrence of PRSV on a weed host in Jamaica. Because of its widespread distribution and potential of serving as a reservoir of PRSV, cerasee may play a role in the epidemiology of PRSV.

References: (1) M. Chin et al. Jam. J. Sci. Technol. 14:58, 2003. (2) D. Purcifull et al. No 292 in: Descriptions of Plant Viruses. CMI/AAB, Surrey, England, 1984. (3) J. Slightom. Gene 100:251, 1991.
Core Rot Development in Red Delicious Apples Is Affected by Susceptibility of the Seed Locule to Alternaria alternata Colonization
Authors: Niem J. , Miyara I. , Ettedgui Y. , Reuveni M. , Flaishman M. , Prusky D.
Published: October 2007

Alternaria alternata is the causal organism of core rot decay symptoms in susceptible cv. Red Delicious but not in resistant cv. Golden Delicious. The two cultivars did not differ in natural colonization of the style and ovary during the first week after full bloom; colonization of the ovary in the susceptible cultivar subsequently decreased with increasing distance from the calycine tube. By 30 days after full bloom, Alternaria recovery from ovary 1, adjacent to the end of the calycine tube, was 100 and 40% in the susceptible and resistant cultivars, respectively. In the susceptible cultivar, Alternaria recovery decreased from 75 to 20% in ovaries 2, 3, and 4, while there was only minor incidence in the resistant cultivar. Inoculation of the mesoderms of the two cultivars induced similar decay symptoms, but inoculated locules of Red Delicious were more susceptible than those of Golden Delicious. Increased inoculum concentration or isolate virulence enhanced the difference in locule susceptibility between the cultivars. Inoculation on isolated seed locules or on media amended with susceptible locule tissue as a carbon source induced greater transcript levels of several genes than the inoculation on resistant tissue. Endo- and exoglucanase activity levels were higher at pH 4.8 than at 4.2, conditions typical of the mesoderm adjacent to the seed locules of the susceptible and resistant cultivars, respectively. Current results suggest that susceptibility of Red Delicious apples to core rot decay is dependent on the sensitivity to locule colonization and on mesoderm pH, a factor that enhances fungal virulence.
Epidemiology of Flavescence Dorée in Vineyards in Northwestern Italy
Authors: Morone C. , Boveri M. , Giosuè S. , Gotta P. , Rossi V. , Scapin I. , Marzachì C.
Published: October 2007

A serious outbreak of flavescence dorée (FD) was reported in Piemonte, northwestern Italy, in 1998, and since then, the disease has compromised the economy of this traditional wine-growing area, even following the application of compulsory insecticide treatments to control Scaphoideus titanus, the vector of the causal phytoplasma. Affected vines show severe symptoms, varying according to the cultivar, and are rogued to reduce disease spread. Following winter and pruning, a previously affected vine may appear symptomless and free of phytoplasmas in its aerial as well as its root system, even by nested-polymerase chain reaction assays. Such plants are considered to be “recovered”. Since 1998 homogenous data on the incidence of newly infected, healthy, or recovered plants productivity, presence of vectors, and treatment schedules have been collected in seven severely affected vineyards of southern Piemonte for 5 years (1999 to 2003). Infectivity and recovery rates were also calculated each year. From 1999 to 2003, the average number of healthy plants decreased and the numbers of recovered plants and those with symptoms increased. Productivity of recovered vines, although lower than that of healthy ones, was always higher than that of vines with symptoms and was not influenced by the time elapsed from date of recovery. The relationships between the ln-transformed number of vectors trapped in the vineyards the previous year and the infection and the recovery rates were fitted by an exponential (R2 = 0.95) and an asymptotic (R2 = 0.93) model, respectively.
Pierce's Disease of Grapevines: Identification of the Primary Vectors in North Carolina
Authors: Myers Ashley L. , Sutton Turner B. , Abad Jorge A. , Kennedy George G.
Published: October 2007

In the past 10 years, the winegrape industry in the southeastern United States has experienced rapid growth; however, further expansion may be inhibited by Pierce's disease (PD). Epidemiological studies were conducted to identify the primary vectors of Xylella fastidiosa, the cause of PD of grape, by surveying sharpshooter population dynamics in the eastern Piedmont and Coastal Plain regions of North Carolina. Sharpshooter species were assessed for the presence of X. fastidiosa in the field. Leafhoppers were trapped in three vineyards in the eastern Piedmont and one vineyard in the northeastern Coastal Plain in 2004 and 2005. Four insects were identified as most abundant: Oncometopia orbona, Graphocephala versuta, Paraphlepsius irroratus, and Agalliota constricta. Adult specimens of O. orbona, G. versuta, and P. irroratus were tested for the presence of X. fastidiosa by nested polymerase chain reaction. In all, 27% of O. orbona, 28% of G. versuta, and 33% of P. irroratus trapped were positive for X. fastidiosa over the two seasons. Transmission experiments demonstrated that both O. orbona and G. versuta have the ability to transmit X. fastidiosa to grape. These vectors are likely to be important in all winegrowing regions of the Southeast, because their presence has been documented throughout the southern states. In DNA analyses, X. fastidiosa strains from insects trapped in North Carolina were genetically similar to one another and to the known “PD strain” from California. This is the first report of these two leafhopper species transmitting X. fastidiosa to grapevines in the Southeast.
Financial Benefit of Using Crop Protection Decision Rules Over Systematic Spraying Strategies
Authors: Fabre F. , Plantegenest M. , Yuen J.
Published: October 2007

Decision rule models are considered to be one of the main cornerstones of the implementation of integrated pest management (IPM) programs. Even if the need for such programs to offer cost advantages over conventional strategies is a major incentive for IPM adoption, few studies focus on this financial dimension. In this article, a modeling approach of the response of a pathosystem to a disease control method and of the predictive performance of decision rules is used to explore how some basic factors act on the likelihood of adoption of decision rule models strategies (such as using an IPM system) over systematic strategies (such as systematic-spraying and never-spraying strategies). Even if the average cost of using the decision rule strategies is always lower than the average cost of systematic strategies in several different scenarios, the models developed here showed strong effects of different pathosystems and decision rules on financial benefits. The number of production situations where decision rules are of interest is highly correlated with their accuracy. However, because of the inescapable trade-offs between decision rule accuracy and limiting factors such as its user-friendly characteristics, the use of decision rules is unlikely to reduce costs to <70% of the costs of systemic strategies. In more general terms, this study provides quantitative guidelines on the financial advantage that decision rules can offer in plant protection as well as a better understanding of their potential usefulness.
Temporal Variation in Setosphaeria turcica Between 1974 and 1994 and Origin of Races 1, 23, and 23N in the United States
Authors: Ferguson L. M. , Carson M. L.
Published: October 2007

Setosphaeria turcica causes northern leaf blight, an economically important disease of maize throughout the world. Survey collections of S. turcica isolates from 1974 to 1994 provided a unique opportunity to examine temporal diversity in the eastern United States. Two hundred forty-two isolates of S. turcica from maize were studied with random amplified polymorphic DNA (RAPD) markers, mating type, and virulence on maize differential inbred lines with known Ht resistance genes to examine changes over time. One hundred forty-nine RAPD haplotypes were identified. Nearly 20% of haplotypes recurred in more than one year. Race 0 isolates declined in frequency from 83% in 1974 to near 50% in the 1990s, most likely in response to the widespread deployment of Ht1 in commercial maize hybrids. Races 23 and 23N were present in the collection at low levels throughout the study period and were also found among isolates from Virginia in 1957. The frequency of MAT1-2 isolates increased sharply after 1979 and was associated with the emergence of race 1 during the same period. RAPD markers were used to investigate the genetic diversity among a subset of isolates collected in the United States from 1976 to 1982, the period in which this dramatic shift in race frequency occurred. Multilocus haplotypes were not exclusively associated with known races of S. turcica. Based on shared haplotypes and cluster analysis, race 1 isolates share greater similarity with race 0 than with 23 or 23N isolates, indicating race 1 probably evolved from multiple lineages of race 0. Sorghum spp.-infecting isolates share greater similarity with one another than with maize-infecting isolates and represent a distinct subgroup.
Recovery and collapse of the Far Eastern sardine
Authors: KAWASAKI T.
Published: October 2007

The Far Eastern sardine (Sardinops sagax) began to increase dramatically in the early 1970s, reached a peak in the late 1980s, but then decreased thereafter. This dramatic recovery and collapse is the second cycle this century, and constitutes part of a long‐term structural change in a pelagic fish community. The new cycle was initiated with higher survival at the earliest stages of sardine on both coasts of central Japan and they spread to the north, south and offshore. Strong year classes were produced at short intervals. The spawning area moved westward and inshore. Collapse was caused by survival failure. The spawning activity shifted to theeast and offshore and the range of the sardine was reduced. Recovery was triggered by global climatic change in a density‐independent manner and the collapse underway is caused by a density‐dependent mechanism. The sardine is the keystone species in the pelagic fish community and changes of mackerel (Scomber japonicus) and anchovy (Engraulis japonicus) populations are in progress.
Loss of myoepithelium is variable in solid papillary carcinoma of the breast
Authors: Nicolas M M , Wu Y , Middleton L P , Gilcrease M Z
Published: October 2007

Aims:  Reports on the frequency of myoepithelial loss in solid papillary carcinoma (SPC) of the breast, an unusual variant of papillary carcinoma with a solid pattern of expansile growth, have been strikingly contradictory. The aim was to clarify the frequency of myoepithelial loss in cases of SPC diagnosed at our institution.

Methods and results:  Eleven cases of SPC with available blocks or unstained slides were retrieved from the M. D. Anderson archives or obtained from outside contributors. Immunohistochemistry for smooth muscle actin (SMA) and p63 was evaluated on the circumscribed nests that appeared to be non‐invasive by haematoxylin and eosin morphology. Three of the 11 cases (27%) were positive for both SMA and p63 at the periphery of all such foci, whereas eight cases (73%) lacked staining for both myoepithelial markers in at least one focus. Of these eight cases, one was diagnosed with only microinvasion, yet metastatic tumour resembling the circumscribed primary SPC was identified in two ipsilateral axillary lymph nodes.

Conclusions:  SPC of the breast frequently lacks myoepithelial markers at the tumour–stromal interface in spite of a circumscribed non‐invasive appearance. Metastases from such tumours are infrequent, but can occur in cases that lack myoepithelial marker expression by immunohistochemistry.
Gastric and intestinal diffuse large B‐cell lymphomas are clinically and immunophenotypically different. An immunohistochemical and clinical study
Authors: Connor J , Ashton‐Key M
Published: October 2007

Aims:  To determine the immunophenotype of gastric and intestinal diffuse large B‐cell lymphomas and investigate the clinical significance of patterns of antigen expression.

Methods and results:  Immunohistochemistry was performed for detection of CD10, Bcl‐6, Bcl‐2, MUM1 and p53 in paraffin‐embedded tissue from 29 patients with primary diffuse large B‐cell lymphoma of the stomach and intestine. Statistical analysis was performed using χ2 and Fisher’s exact tests. Survival data were analysed by the Kaplan–Meier method and compared using a log rank test. Thirteen of the 29 cases were of germinal centre phenotype (CD10+ or CD10–, Bcl‐6+ and MUM1–). Sixteen were of activated B‐cell phenotype (all CD10– and either Bcl‐6–, or Bcl‐6+ and MUM1+). Sixteen cases showed Bcl‐2 expression. There was a statistically significant difference (P < 0.05) in immunophenotype of the neoplastic cells relating to tumour site. Of 15 gastric lymphomas, 11 were of activated B‐cell phenotype and 9/14 intestinal tumours were of germinal centre phenotype. No significant survival difference was found between groups with regard to expression of any of the antigens investigated.

Conclusions:  Primary gastric and intestinal large cell lymphomas appear to show different patterns of antigen expression. This suggests that these tumours arise by different mechanisms and/or from different causes. Gastric diffuse large B‐cell lymphomas are usually of activated B‐cell phenotype that may reflect a relationship with low‐grade gastric lymphomas of marginal zone type. Intestinal diffuse large B‐cell lymphomas usually show a germinal centre phenotype, suggesting an origin from germinal centre B cells. In this study the tumour immunophenotype was not associated with any difference in survival.
Differential suppression of experimental allergic diseases in rats infected with trypanosomes
Authors: MACKENZIE A.R. , SIBLEY P.R. , WHITE B.P.
Published: October 2007

Summary PVG/c rats, infected 3 days previously with 103 Trypanosoma brucei brucei S.42 organisms failed to develop adjuvant disease in response to an intradermal inoculation of mycobacterial adjuvant. By contrast, similarly infected rats, immunized with heterologous brain and spinal cord in Freund's complete adjuvant with pertussis vaccine as a secondary adjuvant, developed clinical signs of allergic encephalomyelitis (EAE) at least as severe as those in uninfected rats.

Delayed hypersensitivity reactions to PPD were depressed in trypanosome‐infected, adjuvant‐injected rats, as were the reactions to myelin basic protein in infected rats developing EAE. There appeared to be no cross‐reactivity between trypanosomal antigen and myelin basic protein which could account for the lack of suppression of EAE.

It is suggested that the different extent to which autoimmunity is involved in these two experimental allergic diseases may account for the differential suppressive activity of trypanosome infections upon them.
Successful vaccination of cats against Brugia pahangi with larvae attenuated by irradiation with 10 krad cobalt 60
Authors: OOTHUMAN P. , DENHAM D.A. , MCGREEVY P.B. , NELSON G.S. , ROGERS ROSEMARY
Published: October 2007

Summary Cats were vaccinated by the inoculation on 10 occasions of approximately 300 larvae of Brugia pahangi which had been irradiated with 10 krad cobalt 60. They were challenged on 3 occasions with normal larvae of either B. pahangi or B. patei. The vaccinated cats were resistant to challenge as demonstrated by either longer pre‐patent periods or failure to become microfilaraemic and by having fewer third, fourth or adult worms than normal controls. Although the vaccination procedure was unpractically heavy these results lend encouragement to the possibility of developing vaccines against filarial infections.
Studies on chronic versus transient intestinal nematode infections in mice I. A comparison of responses to excretory/secretory (ES) products of Nippostrongylus brasiliensis and Nematospiroides dubius worms
Authors: DAY KAREN P. , HOWARD R.J. , PROWSE S.J. , CHAPMAN C.B. , MITCHELL G.F.
Published: October 2007

Summary Previous reports have demonstrated that after implantation of intestinal worms or after exposure to infective third stage larvae, the duration of infection with Nematospiroides dubius is markedly prolonged in intact mice relative to infection with Nippostrongylus brasiliensis. The rapid rejection of N. brasiliensis adults appears T‐cell dependent in that adults persist for longer periods in hypothymic nude mice than in intact mice. Excretory/secretory (ES) products harvested from N. dubius or N. brasiliensis intestinal worms did not differ obviously in the following characteristics: rate of production and degree of complexity of proteins, in vitro mitogenicity, allergenicity, or in their abilities to induce or elicit delayed type hypersensitivity reactions in naive and infected mice, respectively. Two differences between N. brasiliensis‐ and N. dubius‐infected mice were an IgG1 hypergammaglobulinaemia and readily detected anti‐ES precipitating antibodies in the circulation; both responses were confined to the chronic N. dubius infection. One difference between N. brasiliensis and N. dubius ES products was that the former, but not the latter, induced protection against homologous infection when injected with Freund's complete adjuvant. By contrast, intraperitoneal implantation of either type of adult worm induced protection against homologous infection at least in female Balb/c mice. After intestinal implantation of both N. dubius and N. brasiliensis intestinal worms, the rejection of N. brasiliensis was not influenced by, nor did it alter, persistence of N. dubius adults. In support of conclusions drawn by others, the differences in persistence of infection between these two nematodes probably reflect differences in the ability to resist both specific and nonspecific components of the complex intestinal rejection process. The chronicity of N. dubius infection and nonpersistence of N. brasiliensis
A comparison between a new serological method, thin layer immunoassay (TIA), and the enzyme‐linked immunosorbent assay (ELISA) for the detection of antibodies in schistosomiasis
Authors: ISMAIL M. , DRAPER C. , OUCHTERLONY Ö. , NILSSON L.‐Å. , TERRY R.
Published: October 2007

Summary A comparison has been made of a new serological method, thin layer immunoassay (TIA), and an established method, enzyme‐linked immunosorbent assay (ELISA), in the detection and quantification of antibodies in schistosomiasis. Using sera from known S. haematobium and S. mansoni cases, the performance of the two tests was almost identical; 95.6% positive for TIA and 96.4% by ELISA. TIA however produced a small number of false positives with sera from other helminth infections whereas ELISA gave none. There was excellent correlation between the tests in the quantification of anti‐S. haematobium antibodies, both in human cases and in infected baboons. TIA has the advantage of being extremely simple to perform, but has the disadvantage of requiring a higher concentration of antigens.
Altered intestinal fluid movement in response to Trichinella spiralis in immunized rats
Authors: CASTRO G.A. , HESSEL J.J. , WHALEN G.
Published: October 2007

Summary Net intestinal fluid movement was measured in immunized and non‐immunized rats infected with the enteric stages of the nematode, Trichinella spiralis. Animals were studied 30 min, 5 days and 30 days after receiving infective larvae. Net water movement across the mucosal surface of the gut was measured in vivo by perfusing a cannulated segment (approximately 30 cm) of proximal small intestine with an isotonic solution containing a nonabsorbable marker, 14C polyethylene glycol, at a rate of 0.5 ml/min. Uninfected rats showed net absorption of water. 25 μl/h per cm of intestine. This response was unaltered when rats were infected (7 times 103 larvae/rat) and examined 30 minutes later. Five days after primary infection net tissue‐to‐lumen fluid movement, ie. net secretion, occurred at a rate of 45 μl/h per cm. When rats were studied 30 days after primary infection, net absorption equivalent to the preinfection level was observed once again. Previously infected (immunized) rats, when challenged (secondary infection, 7 times 103 larvae/rat) and examined within 30 min showed a significant decrease in net absorption rate as compared with non‐immunized rats. Absorption returned to the preinfection level at both 5 and 30 days post challenge. Results support the conclusion that T. spiralis caused a decrease in net lumen‐to‐tissue fluid movement during primary and secondary infections. The response was initiated faster in previously infected hosts. The rapid induction of net fluid movement in the direction of secretion upon secondary contact with the parasite is associated temporally with prevention of worm establishment.
Modulation by malaria infection of the induction of T lymphocyte‐dependent delayed‐type hypersensitivity and antibody formation to sheep erythrocytes in mice
Authors: J.C. MICHEL  , P.H. LAGRANGE  , B. HURTREL
Published: October 2007

Summary A profound alteration of the inductive phase of delayed‐type hyper‐sensitivity and antibody formation to SRBC was found in malaria infected mice when sensitization with this antigen was performed intravenously at a critical time of the disease, but not after subcutaneous immunization, suggesting a major role for the spleen in the mechanism of immunodepression.