bluuebunny/crossref_metadata_2025_split huggingface dataset:
White rust (Albugo candida) resistance loci on three Arabidopsis chromosomes are closely linked to downy mildew (Peronospora parasitica) resistance loci
Authors: Borhan Mohammad H. , Brose Edemar , Beynon Jim L. , Holub Eric B. 
Published: March 2003

SummaryTwo accessions of Arabidopsis thaliana (Ksk‐1 and Ksk‐2) were used to identify and map three loci (RAC1, RAC2 and RAC3) of genes that confer Resistance to Albugo candida (white rust). The phenotypes associated with these genes were classified as either FN (necrotic flecks on upper surface of cotyledons and no blisters) for RAC2 and RAC3, or FYN (flecks surrounded by yellowing and no blisters) for RAC1. Both phenotypes exhibited rapid death of host cells penetrated by the parasite (hypersensitive response), with callose deposition commonly encasing the haustorium. F6 recombinant inbred lines were produced specifically for the purpose of mapping each RAC locus relative to molecular markers. Dominant resistance at the locus RAC1 in Ksk‐1 was previously mapped to chromosome 1 between RFLP markers m253 and m254, and co‐segregating with a downy mildew resistance specificity RPP9 in the accession Wei‐0. We report here a fine‐scale map interval and co‐segregating markers for this locus, which in turn enabled mapping of a previously unnoticed source of resistance in Ksk‐1 designated RAC3 that exhibits an FN phenotype hyperstatic to the FYN phenotype of RAC1. RAC3 is closely linked to the RPP8/HRT on chromosome 5, a locus which contains specificities for resistance to downy mildew and turnip crinkle virus. Recombinant inbreds also enabled mapping of recessive resistance at RAC2 in Ksk‐2 to the bottom arm of chromosome 3, in the 6 cM interval between two downy mildew resistance loci (RPP1 and RPP13).
Characterization of a 20 kDa DNase elicitor from Fusarium solani f. sp. phaseoli and its expression at the onset of induced resistance in Pisum sativum
Authors: Klosterman Steven J. , Chen Junping , Choi Jane J. , Chinn Ellen E. , Hadwiger Lee A. 
Published: March 2003

SummaryDNase released from Fusarium solani f. sp. phaseoli (Fsph DNase) has previously been reported to induce pathogenesis‐related (PR) genes, phytoalexin accumulation and disease resistance against subsequent challenge with the true pea pathogen, Fusarium solani f. sp. pisi (Fspi). This report is a further analysis of DNase production with probes specific for both the gene and protein. N‐terminal analysis of the ≈20 kDa Fsph DNase protein facilitated both the development of anti‐Fsph DNase antiserum and the cloning of the Fsph DNase gene. Utilizing the anti‐Fsph DNase antiserum to prepare an affinity column, we demonstrated that the retention and recovery of the DNase activity was associated with this protein. Fsph DNase protein was detectable by Western analysis in both the fungi and plant cytoplasm within 6–8 h following inoculation of the pea endocarp surface. Partially purified DNase detected via catalytic activity began accumulating within pea tissue at 3 h post‐inoculation. Enhanced fragmentation of pea DNA occurred within 5 h following treatment of pods with Fsph DNase or inoculations with the two fungi. DNA cleavage within the nuclei of endocarp pea cells was detectable via a TUNEL assay at 3 h post‐inoculation. As a result of these findings, we propose that the entrance of Fsph DNase into the pea cell and the signalling of plant defence responses is temporally associated with the damage of host DNA.
Isolation and characterization of novel defence‐related genes induced by copper, salicylic acid, methyl jasmonate, abscisic acid and pathogen infection in Brassica carinata
Authors: Zheng Zhifu , Uchacz Tina M. , Taylor Janet L. 
Published: March 2003

SummaryTo examine the defence response in Brassica carinata we differentially screened a cDNA library made from CuCl2‐treated (Cu) leaves. The sequence of 17 of the 27 cDNA clones examined that showed Cu‐induction had a high similarity to defence genes from other plant species. Among other clones that showed higher expression in the Cu leaves were two cDNAs encoding polypeptides of 351 and 250 amino acids, designated BcCJS1 and BcCJAS1. BcCJS1 had similarity to S‐adenosyl‐l‐methionine: salicylic acid carboxyl methyltransferase from Clarkia breweri. However, the enzyme activity was not found in extracts from E. coli expressing BcCJS1. BcCJAS1 did not show extensive similarity to any genes with known function in the databases but it did contain three regions of amino acid sequence that are frequently found in amidotransferases. A third Cu‐induced mRNA, Bcp6PGL, showed very high (86%) similarity to a putative 6‐phosphogluconolactonase (6PGL) from Arabidopsis thaliana. In addition to Cu induction, BcCJS1 expression was induced by methyl jasmonate (MeJA) and salicylic acid (SA), BcCJAS1 expression by MeJA, SA and abscisic acid and Bcp6PGL expression by MeJA. The expression of all three genes increased after Alternaria brassicae infection. BcCJS1 and BcCJAS1 were induced within 1 h after MeJA‐ but not until 3 h after SA‐treatment. The expression of both genes was systemically induced after infection with a compatible or incompatible fungal pathogen. SA systemically induced only BcCJAS1. The effects of various inhibitors of signalling pathways on expression of the three genes were studied.
Identification of gene expression differences between Globodera pallida and G.‘mexicana’ by suppression subtractive hybridization
Authors: Grenier Eric , Blok Vivian C. , Jones John T. , Fouville Didier , Mugniéry Didier 
Published: March 2003

Summary Globodera pallida
and
G.
‘
mexicana
’ are closely related nematode species that can mate and form viable hybrids on tomato but usually develop on different Solanaceous plants. Identification of nematode genes involved in parasitism is important for elucidation of disease resistance mechanisms in plants. In this study, we have used suppression subtractive hybridization (SSH) to investigate differences between the transcriptomes of
G. pallida
and
G.
‘
mexicana
’ J2s. This provides a basis for further studies characterizing pathogenicity factors in these nematodes. None of the cDNA fragments isolated in the SSH experiments appeared to be completely absent from the other transcriptome. Differences in expression levels of some of the isolated cDNAs between the two species were detected. Sequence analysis revealed that nearly 85% of the cloned sequences are nematode specific and a high proportion were pioneer genes for which no putative homologues were present in the databases. However, homologues of a cellulase and a putative pathogenicity factor previously described from
G. rostochiensis were isolated. The putative roles of these sequences in parasitism are discussed.
Barley yellow dwarf virus: Luteoviridae or Tombusviridae?
Authors: Miller W. Allen , Liu Sijun , Beckett Randy 
Published: March 2003

Summary Barley yellow dwarf virus
(BYDV), the most economically important virus of small grains, features highly specialised relationships with its aphid vectors, a plethora of novel translation mechanisms mediated by long–distance RNA interactions, and an ambiguous taxonomic status. The structural and movement proteins of BYDV that confer aphid transmission and phloem‐limitation properties resemble those of the
Luteoviridae
, the family in which BYDV is classified. In contrast, many genes and
cis
‐acting signals involved in replication and gene expression most closely resemble those of the
Tombusviridae .Taxonomy: BYDV is in genus Luteovirus, family Luteoviridae. BYDV includes at least two serotypes or viruses: BYDV‐PAV and BYDV‐MAV. The former BYDV‐RPV is now Cereal yellow dwarf virus‐RPV (CYDV‐RPV). CYDV is in genus Polerovirus, family Luteoviridae. Genus Luteovirus shares many features with family Tombusviridae.Physical properties: ∼25 nm icosahedral (T = 3) virions. One major (22 kDa) and one minor (50–55 kDa) coat protein. 5.6–5.8 kb positive sense RNA genome with no 5′‐cap and no poly(A) tail.Host range: Most grasses. Most important in oats, barley and wheat. Also infects maize and rice.Symptoms: Yellowing and dwarfing in barley, stunting in wheat; reddening, yellowing and blasting in oats. Some isolates cause leaf notching and curling.Key attractions: Model for the study of circulative transmission of aphid‐transmitted viruses. Plethora of unusual translation mechanisms. Evidence of recombination in recent evolutionary history creates taxonomic ambiguity. Economically important virus of wheat, barley and oats, worldwide.Useful websites/meetings: International symposium: ‘Barley Yellow Dwarf Disease: Recent Advances and Future Strategies’, CIMMYT, El Batan, Mexico, 1–5 September 2002, http://www.cimmyt.cgiar.org/Research/wheat/Conf_BYD_02/invitation.htm http://www.cimmyt.org/Research/wheat/BYDVNEWS/htm/BYDVNEWS.htm Aphid transmission animation: http://www.ppws.vt.edu/~sforza/tmv/bydv_aph.html
Identification of regulators of hrp/hop genes of Erwinia carotovora ssp. carotovora and characterization of HrpLEcc (SigmaLEcc), an alternative sigma factor
Authors: Chatterjee Asita , Cui Yaya , Chaudhuri Shubho , Chatterjee Arun K. 
Published: March 2003

Summary Erwinia carotovora ssp. carotovora (Ecc) possesses hrpNEcc[hrp = gene for hypersensitive reaction (HR) and pathogenicity], the structural gene for HarpinEcc, the inducer of the HR‐like response and genes for the type III secretion system. In Ecc, RsmA, an RNA‐binding protein responsible for the accelerated decay of RNA species, tightly controls the expression of the Hrp regulon. We document here that Ecc strain 71 possesses several presumed Hrp regulators: HrpXEcc, HrpYEcc, HrpSEcc, and HrpLEcc. Nucleotide sequence data indicate that the regulatory genes occur as a cluster. The data also suggest that HrpXEcc is a putative sensor kinase, HrpYEcc is the cognate response regulator, and HrpSEcc is an NtrC‐like regulator. hrpLEcc consists of a 543‐bp open reading frame (ORF), which encodes a c. 21‐kDa protein product. This protein shares significant homology with members of the extracytoplasmic function (ECF) subfamily of alternative sigma factors, including SigE. To examine the regulatory role of hrpLEcc, we constructed by marker exchange an HrpLEcc− derivative of an RsmA− strain. The levels of transcripts of hrcCEcc, a gene for the type III secretion system, and hrpNEcc were lower in the RsmA−HrpLEcc− mutant compared to its RsmA−HrpLEcc+ parent. The RsmA−HrpLEcc− strain, like the RsmA−HrpLEcc+ parent, caused maceration of celery petioles and produced extracellular pectinases, cellulase, and protease, indicating that the alternative sigma factor is not required for the type I and type II secretion systems, for tissue maceration, or for the production of proteins secreted by these pathways. However, the RsmA−HrpLEcc− strain, unlike the RsmA−HrpLEcc+ strain, did not elicit the HR in tobacco leaves. In addition, the RsmA−HrpL− strain failed to cause symptoms in Arabidopsis thaliana. Genetic and biochemical data revealed that HarpinEcc is required for symptom production in Arabidopsis, but is not sufficient by itself to cause necrosis. These observations raise the possibility that another ‘effector’ protein of Ecc, secreted by the type III system, acts in conjunction with HarpinEcc to trigger responses resulting in cell death in Arabidopsis.
Beet yellows virus: the importance of being different
Authors: Dolja Valerian V. 
Published: March 2003

SUMMARYTaxonomic relationship: Type member of the genus Closterovirus, family Closteroviridae. A member of the alphavirus‐like supergroup of positive‐strand RNA viruses. Physical properties: Virions are flexuous filaments of ∼1300 nm in length and ∼12 nm in diameter that are made up of a ∼15.5 kb RNA and five proteins. The major capsid protein forms virion body of helical symmetry that constitutes ∼95% of the virion length. The short virion tail is assembled by the minor capsid protein, Hsp70‐homologue, ∼64‐kDa protein, and ∼20‐kDa protein. Viral proteins: The 5′‐most ORFs 1a and 1b encode leader proteinase and RNA replicase. The remaining ORFs 2–8 are expressed by subgenomic mRNAs that encode 6‐kDa membrane protein, Hsp70 homologue, ∼64‐kDa protein, minor and major capsid proteins, ∼20‐kDa protein, and ∼21‐kDa protein, respectively. Hosts: The principal crop plants affected by Beet yellows virus (BYV) are sugar beet (Beta vulgaris) and spinach (Spinacea oleracea). In addition, BYV was reported to infect ∼120 species in 15 families. Most suitable propagation species are Nicotiana benthamiana, Tetragonia expansa, and Claytonia perfoliata.
Health information services: a submission to LISC by the Library Association on behalf of its Medical, Health and Welfare Libraries Group
Authors: WILLIS ANNE 
Published: March 2003

The Library Association Medical, Health and Welfare Libraries Group was asked by the Library and Information Services Council (LISC) for England to submit a paper on health information services for the lay person and this presented a timely opportunity to consider the situation thus far and possibilities for the future. A working group was set up from amongst those active in the field to pool ideas and experience, and it was fortunate also in being able to include consideration of Elaine Kempson's recently published study Informing health consumers. It was felt particularly that whilst a number of worthwhile services were developing there was no guarantee of adequate local provision and that in the absence of any sort of framework there was considerable danger of duplication of effort and isolation on the part of the practitioners.The paper was considered by LISC in October 1988 and in the intervening period our recommendation that public library development incentive funding might be used to enable a public library to co‐operate with other local statutory and voluntary agencies in the setting up of a pilot local health information centre, perhaps capitalizing on existing expertise by buying‐in a database such as that of Help for Health, has been fulfilled by the establishment of the Dorset Health Information Service whose progress will be watched with interest.Nevertheless there is still much to be achieved in this field and it is hoped that this paper will prove a useful basis for continued discussion.
Delivery of health informatics education and training
Authors: Brittain J. Michael , Norris A. C. 
Published: March 2003

AbstractAn overview is provided of education and training in health information management in the context of national information strategies. Although the article focuses upon British programmes, there are examples from North America, Australasia and other countries. Reference is made to international activities in the development of generic courses for education and training, the need for education and training, the content of courses, and methods of delivery, including Internet‐based training and education. Governments and health authorities in many countries have recognized the urgent need for a highly educated and trained workforce in information management, but universities have been slow to respond, until the last few years. However, there is now a plethora of education and training programmes in North America, most European countries, and Australasia.
Apoptosis in thyroid neoplasms: relationship with p53 and bcl‐2 expression
Authors: Moore  , Ohene‐Fianko  , Garcia  , Chakrabarti  
Published: March 2003

Aim:Cell gain and loss occurs concurrently in tumours. Apoptosis may play a major role in determining the growth and aggressiveness of the tumours. The aim of this study was to investigate whether apoptosis is related to the degree of differentiation and expression of mutated p53 and bcl‐2 in thyroid neoplasms.Methods and results:Fifty‐three thyroid tumours of various histological types and 10 multinodular goitres were investigated semiquantitatively for the presence of apoptosis using a DNA end ligase method. Simultaneously, quantitative immunostaining was performed for bcl‐2 and p53, two known regulators of apoptosis. No apoptosis was detected in normal thyroid tissues, multinodular goitres and in four follicular adenomas, all of which were positive for bcl‐2. On the other hand, two anaplastic and one insular carcinomas showed marked increase in apoptosis along with intense p53 positivity and bcl‐2 negativity. The majority of the follicular carcinomas showed results similar to that of follicular adenomas. No apoptosis was detected in 41% of papillary carcinomas, the majority of these being p53 negative and bcl‐2 positive. Forty‐four per cent of the papillary carcinomas demonstrated low apoptosis rate, with variable bcl‐2 positivity and mostly negative for p53. Fifteen per cent of papillary carcinomas showed a high apoptosis rate. They were p53 negative and mostly negative for bcl‐2. The differences of staining in various tumours with respect to p53, bcl‐2 and apoptosis were statistically significant. Correlation analysis demonstrated a significant relationship between apoptosis and bcl‐2 expression in thyroid tumours (P < 0.001), whereas no relationship was seen with p53.Conclusion:These data suggest that bcl‐2 expression in thyroid neoplasms is related to apoptosis. p53 expression is associated with high grade thyroid tumours, but may not be important in the apoptotic pathways in all thyroid tumours.
Spontaneous regression of hepatocellular carcinoma
Authors: Kaczynski  , Hansson  , Remotti  , Wallerstedt  
Published: March 2003

Aims:To determine the clinical and histopathological features of a case of a spontaneous regression of hepatocellular carcinoma (HCC).Case details:HCC was found incidentally in a 73‐year‐old man during a laparotomy for evaluation of gastric retention. Despite no treatment being given, he improved gradually with no sign of tumour as evidenced by coeliac angiography 15 months later, as well as by explorative laparotomy after another 2 years. The patient died 15 years after the primary diagnosis of HCC, without known evidence of tumour recurrence. The patient's clinical records were reviewed, and paraffin‐embedded liver tissue was re‐evaluated. Both histological and immunohistochemical features were compatible with the diagnosis of a well differentiated HCC. Conceivable causes of the spontaneous regression of this and other reported cases are discussed, but the phenomenon remains enigmatic.Conclusions:This case with a histologically proven HCC and a very long follow‐up time confirms that spontaneous regression does occur. Since the case was found incidentally our report also implies that this may not be as rare as reported.
Metallothionein and apoptosis in primary human hepatocellular carcinoma and metastatic adenocarcinoma
Authors: Deng  , Chakrabarti  , Waalkes  , Cherian  
Published: March 2003

Aims:Differences in expression of metallothionein (MT) have been reported in various human tumours. MT is mainly expressed in proliferating epithelial tumour cells but in human hepatocellular carcinoma (HCC) there is only a minimal expression of MT. Since MT is a zinc binding protein and certain inducers of MT including zinc play a role in apoptosis, studies were undertaken to compare the expression of MT and the presence of apoptotic cells (APPC) in both primary HCC and metastatic adenocarcinoma.Methods and results:Histological sections of 13 cases of primary HCC and eight cases of metastatic adenocarcinoma were obtained from archival samples. They were stained for MT using a polyclonal antibody which cross‐reacts readily with human MT and for APPC by the TUNEL technique. Normal human liver had consistent MT staining with no detectable APPC. The primary HCC showed moderate MT staining with a small number of APPC while metastatic adenocarcinoma showed no MT staining with a large number of APPC.Conclusions:These results suggest a relationship between absence of MT and appearance of APPC in human liver tumours, especially in metastatic adenocarcinomas.
De‐differentiated chondrosarcoma is not a ‘de‐differentiated’ chondrosarcoma
Authors: Aigner T , Dertinger S , Neureiter D , Kirchner T 
Published: March 2003

Aims: De‐differentiated chondrosarcoma is characterized by the presence of two distinct chondroid and nonchondroid tumour portions. The aim of our study was to investigate the distribution of extracellular matrix components in this tumour entity and thus to shed light on its histogenetic origin.Methods and resultsHistochemical and immunohistochemical analyses were performed for collagen subtypes I, II, III and VI and cartilage proteoglycans in three samples of de‐differentiated as well as conventional chondrosarcomas (various grades). In the chondroid tumour areas of de‐differentiated chondrosarcoma, typical cartilage matrix components could be detected similar to chondroid areas of grade 1 and 2 conventional chondrosarcomas. In contrast, the tumour matrix of the nonchondroid portions of de‐differentiated chondrosarcomas contained matrix molecules which are typical for fibroblastic tissue. This matrix composition was not identical with less differentiated (nonchondroid) areas of grade 2 and 3 conventional chondrosarcomas.ConclusionsOur results confirm the chondroid nature of the differentiated portion of de‐differentiated chondrosarcoma and indicate a nonchondrocytic nature of the nonchondroid portion. De‐differentiated chondrosarcoma should not be considered as a ‘de’‐differentiated chondrosarcoma (grade 4 neoplasm), but as a tumour entity showing two types of mesenchymal differentiation.
Male adnexal tumour of probable Wolffian origin occurring in a seminal vesicle
Authors: Middleton L P , Merino M J , Popok S M , Ordonez N G , Ayala A G , Ro J Y 
Published: March 2003

Aims: Adnexal tumours of probable Wolffian origin are rare low‐grade malignant neoplasms that have been previously described in the broad ligament, ovaries and retroperitoneum of females. All are characterized by small, bland epithelial cells growing in a diffuse, trabecular, or tubular pattern. The majority of the cases reported have pursued a benign clinical course. However, recurrences and distant metastases have been described. We present a case of a male adnexal tumour of probable Wolffian origin occurring in the left seminal vesicle of a 29‐year‐old man with 23 years of follow‐up.ResultsThe diagnosis is supported by immunohistochemical and electron microscopic findings: The tumour cells were immunoreactive for cytokeratin and vimentin while smooth muscle antigen and S100 protein were uniformly negative. By electron microscopy cells were arranged in an acinar pattern and surrounded flocculent, electron‐dense material. Individual cells contained numerous dense bodies and free ribrosomes. The patient had recurrences at 14 and 23 years after initial diagnosis.ConclusionThis is the first report of this entity in a male. The literature on this unusual tumour is reviewed and the clinicopathological, immunohistochemical and ultrastructural features are described. The differential diagnosis of this seemingly indolent tumour is discussed with genitourinary tumours having a more aggressive clinical course.
Primary primitive neuroectodermal tumour of the parotid gland
Authors: Deb R A , Desai S B , Amonkar P P , Aiyer P M , Borges A M 
Published: March 2003

AimsPrimitive neuroectodermal tumour (PNET) is a malignant small round cell tumour that exhibits neuroepithelial differentiation. Isolated cases of PNET have been reported in visceral sites such as the kidney, uterus, ovary, testis, urinary bladder and pancreas. We present two cases of PNET of the parotid gland.Methods and resultsThe first case was a 60‐year‐old woman, who presented with a parotid swelling of 10 months duration. The second case was a 45‐year‐old man, who presented with a recurrent temporofacial swelling of 6 months duration. Histological evaluation, in conjunction with immunohistochemistry, confirmed the diagnosis of PNET.ConclusionsThis is the first documentation of PNET of the salivary gland. The probable origin is from the facial nerve.