bluuebunny/crossref_metadata_2025 huggingface dataset:
Predicting epidemics of yellow rust (Puccinia striiformis) on the upper canopy of wheat from disease observations on lower leaves
Authors: Young C. S. , Paveley N. D. , Vaughan T. B. , Thomas J. M. , Lockley K. D.
Published: June 2003

Data from field experiments were used to test whether disease observations on lower leaves of wheat were good predictors of future epidemic development in the upper canopy. Fungicide treatments to replicated plots in 1994 and 1995 caused variation in levels of initial inoculum of urediniospores of yellow rust (Puccinia striiformis). Observations of symptom severity were made on individual leaf layers throughout the season. Sporulating lesions on lower leaves were considered to be a measure of inoculum source strength for transfer to upper culm leaves. Low source strengths were associated with delays in epidemic development on the upper leaves, as quantified by a location parameter, tm, the time at which severity reached half of the asymptote value in logistic fits to disease progress data on the upper leaves. However, there was much unexplained variation, probably due to extraneous variation in upward transfer efficiency of inoculum and rates of epidemic development. Vanderplank's sanitation ratio theory was used to account for variation in inoculum transfer and epidemic rate. The analysis revealed that if the aim is to predict disease on a newly emerged culm leaf, during the period when it can be treated effectively with fungicide, then observations of disease two leaves further down the culm were of the greatest predictive value (R2 = 86%). These observations, however, need to be integrated with information about factors affecting upward inoculum transfer and rates of epidemic development if acceptable predictive precision is to be achieved.
Seasonal distribution of phytoplasmas in Australian grapevines
Authors: Constable F. E. , Gibb K. S. , Symons R. H.
Published: June 2003

The distribution and persistence of phytoplasmas were determined in Australian grapevines. Phytoplasmas could be detected using the polymerase chain reaction (PCR) from shoots, cordons, trunks and roots throughout the year, and phytoplasmas appear to persistently infect Australian grapevines from year to year. Phytoplasmas were not always detected in samples from the same sampling area from one sampling period to the next. Phytoplasma detection by PCR was improved by sampling from shoots, cordons and trunks, especially during October (early spring). The diseases expressed by the 20 grapevines used in the distribution and persistence studies were monitored. Australian grapevine yellows disease (AGY) was expressed by 17/20 grapevines at some time during the study, whilst only 4/20 and 15/20 grapevines expressed restricted growth disease (RG) and late season leaf curl disease (LSLC), respectively. All grapevines with RG and LSLC also had AGY. The three diseases were persistently expressed in some grapevines and remission of disease was observed in others. The results of PCR detection in the same grapevines indicated that phytoplasmas were more frequently detected in AGY‐affected grapevines that also expressed RG and LSLC compared with grapevines expressing AGY alone. Phytoplasmas were detected in symptomless plant material but less frequently compared with AGY‐affected material.
Pseudomonas populations causing pith necrosis of tomato and pepper in Argentina are highly diverse
Authors: Alippi A. M. , Dal Bo E. , Ronco L. B. , López M. V. , López A. C. , Aguilar O. M.
Published: June 2003

Pseudomonas species causing pith necrosis symptoms on tomato and pepper collected in different areas of Argentina were identified as Pseudomonas corrugata, P. viridiflava and Pseudomonas spp. Their diversity was analysed and compared with reference strains on the basis of their phenotypic characteristics, copper and antibiotic sensitivity tests, serology, pathogenicity, DNA fingerprinting and restriction fragment length polymorphism (RFLP) analysis of a 16S rRNA gene fragment. All P. corrugata strains tested were copper‐resistant while P. viridiflava strains were more variable. Numerical analysis of phenotypic data showed that all P. corrugata strains formed a single phenon that clustered at a level of about 93%, while all the P. viridiflava strains clustered in a separated phenon at a level of 94%. Genomic analysis by repetitive (rep)‐PCR and 16S rRNA‐RFLP fingerprinting and serological analysis showed that the two species contained considerable genetic diversity. Inoculations of tomato and pepper plants with strains from both hosts caused similar pith necrosis symptoms. Strains of both P. corrugata and P. viridiflava were grouped according to their geographical origin and not according to the original host. This is the first report of Pseudomonas viridiflava causing pith necrosis on pepper.
Tomato leaf curl geminivirus in Australia: occurrence, detection, sequence diversity and host range
Authors: Stonor J. , Hart P. , Gunther M. , DeBarro P. , Rezaian M. A.
Published: June 2003

The occurrence of whitefly transmitted geminiviruses in Australia was studied using a mixed DNA probe capable of detecting a range of distinct geminiviruses. The only geminivirus species detected was Tomato leaf curl virus (TLCV), which is spread across a vast geographical region of far‐northern coastal Australia, an area inhabited by the Australasian‐Oceania biotype of Bemisia tabaci. The newly introduced silverleaf whitefly, B. tabaci biotype B, forms high population densities in the eastern coastal region of Queensland and is currently located approximately 150 km from the nearest known TLCV‐infected area. The viral host range appeared to be narrow and of 58 species of crop plants and weeds inoculated using the B biotype, only 11 became infected with the virus, including five that did not show foliar symptoms. A DNA fragment of 694 nt, including the complete C4 open reading frame (ORF), the overlapping N‐terminal part of the C1 ORF and the viral iterons involved in replication, was amplified from 11 TLCV field isolates and sequenced. Sequence analysis revealed an overall sequence variation of up to 14% in this region, as well as the presence of distinct viral iterons.
Characterization of a strain of Apple stem grooving virus in Actinidia chinensis from China
Authors: Clover G. R. G. , Pearson M. N. , Elliott D. R. , Tang Z. , Smales T. E. , Alexander B. J. R.
Published: June 2003

A new strain of Apple stem grooving virus (ASGV) has been identified in Actinidia chinensis imported from China. The leaves of these plants exhibited a variety of symptoms including interveinal mottling, chlorotic mosaics and ringspots. Capillovirus‐like particles were observed under the electron microscope, and the virus could be mechanically transmitted to a range of herbaceous indicators. The virus was detected using ELISA with antisera raised against ASGV. Sequencing of the virus revealed that it had more than 95% amino acid identity with ASGV in the putative coat and movement proteins. From the morphological, transmission, serological and molecular evidence, it was concluded that the virus is a strain of ASGV. It is not known how this strain of ASGV is transmitted, other than by grafting, nor is it known what effect the virus has on the growth of infected vines. The Actinidia‐infecting strain of ASGV does not occur in New Zealand, and infected plants will not be released from quarantine. The detection methods used during the research will assist quarantine and the safe movement of breeding material.
Genetic variation among asexual progeny of Phytophthora infestans detected with RAPD and AFLP markers
Authors: Abu‐El Samen F. M. , Secor G. A. , Gudmestad N. C.
Published: June 2003

Genotypic variation among 32 single‐zoospore isolates (SZI) of Phytophthora infestans, derived asexually from two hyphal‐tip parental isolates (PI‐105 and PI‐1) of the US‐8 genotype, was assessed with 80 random amplified polymorphic DNA (RAPD) primers and 18 amplified fragment length polymorphic DNA (AFLP) primer pairs. In previous investigations, the SZIs from parental isolate PI‐105 showed high levels of virulence variability and were differentiated into 14 races, whereas the SZIs from PI‐1 showed identical virulence to the parent. The purpose of this investigation was to determine if phenotypic variation observed among SZIs of P. infestans could be detected at the DNA level in these isolates. Polymorphism was detected with 51 RAPD primers and with all 18 AFLP primer pairs in PI‐105 SZIs. In SZIs from PI‐1, polymorphism was also detected with 25 RAPD primers and 17 AFLP primer pairs. Cluster analysis using the unweighted pair‐group method with arithmetic averages (UPGMA) separated the SZIs from parent PI‐105 into six virulence groups, 11 RAPD groups and three AFLP groups. Cluster analysis of PI‐1 SZIs, which all belong to the same virulence group, differentiated them into four RAPD groups and six AFLP groups. No close correlation among RAPD, AFLP and virulence groups could be established within the two progenies of SZIs. Results of this study suggest that there is a considerable level of inherent genetic variability among SZIs derived asexually from the same parental isolate. The possible mechanisms and implications of this genetic variation are discussed.
Nematicidal activity of essential oils and organic amendments from Asteraceae against root‐knot nematodes
Authors: Pérez M. P. , Navas‐Cortés J. A. , Pascual‐Villalobos M. J. , Castillo P.
Published: June 2003

The essential oil of Chrysanthemum coronarium flowerheads showed strong nematicidal activity in vitro and in growth‐chamber experiments. Essential oil concentrations of 2, 4, 8 and 16 µL mL−1, significantly reduced hatch, J2 survival (determined by final value and area under curves of cumulative percentage hatch or mortality) and reproduction rate of Meloidogyne artiellia in vitro, with the lowest values occurring at 16 µL mL−1. In pot trials with chickpea cv. PV 61, essential oil concentrations of 10–40 µL per 500 cm3 soil, applied on sterile cotton pellets, also significantly reduced the nematode's reproduction rate. The biological processes of mortality and hatching/reproduction were adequately described by the monomolecular and expanded negative exponential models, respectively. Effectiveness of soil amendment with either flowers, leaves, roots or seeds of C. coronarium, and flowers from several species of Asteraceae (Chrysanthemum segetum, Calendula maritima, Calendula officinalis and Calendula suffruticosa) at 5 g per 500 cm3 soil was tested for suppression of M. artiellia and growth of chickpea cv. PV 61 under growth‐chamber conditions. In these tests, flowers of all five Asteraceae species and various parts of C. coronarium significantly reduced reproduction rates of M. artiellia, by 83·0–95·9%, with the minimum rates occurring in infected chickpea plants amended with flowers of C. officinalis and C. suffruticosa. The in vitro and in planta results suggest that the essential oil of C. coronarium and organic amendments from Asteraceae species may serve as nematicides.
Studies on thiabendazole resistance of Penicillium expansum of pears: pathogenic fitness and genetic characterization
Authors: Baraldi E. , Mari M. , Chierici E. , Pondrelli M. , Bertolini P. , Pratella G. C.
Published: June 2003

Isolates of Penicillium expansum recovered from stored pears were scored for resistance to the fungicide thiabendazole (TBZ) and for pathogenic fitness. Out of 50 isolates, nine were sensitive (S) and 41 resistant (R or RR). Seven of these resistant isolates (RR) germinated with a higher percentage on TBZ‐amended medium than on unamended medium. Six S isolates and six RR isolates were chosen at random for further analysis. S and RR isolates had similar in vitro growth fitness, although RR isolates were characterized by higher infection severity on fruits. Laboratory‐induced resistant isolates were generated by UV‐irradiating S strains, and a similar correlation between the induced TBZ resistance and pathogenic fitness was observed. The β‐tubulin gene of RR and S isolates was amplified and sequenced; mutations correlating with TBZ resistance were identified at residues Phe 167 and Glu 198. Analogous mutations were detected in the laboratory‐induced resistant isolates.
Stability of partial resistance in potato cultivars exposed to aggressive strains ofPhytophthora infestans
Authors: Flier W. G. , Van Den Bosch G. B. M. , Turkensteen L. J.
Published: June 2003

Potato cultivars were evaluated for their resistance responses to aggressive strains ofPhytophthora infestansin field and laboratory experiments. Analysis of variance revealed differential cultivar‐by‐isolate interactions for both foliar and tuber blight resistance. Differential responses occur as revealed by specific susceptibilities of cultivars to certain pathogen genotypes and changing rank order. In general, severity of late blight epidemics as observed in the haulms did not correlate well with foliar blight resistance ratings as presented in the National List of Recommended Potato Varieties. No significant correlation was found between tuber blight incidence under field conditions and the tuber blight rating in the National List. Also, there was no relation between the field and laboratory tuber blight resistance assessments. A significant association was demonstrated between late blight infection in the foliage and tuber blight incidence under field conditions. The presence of differential interaction, independent of R‐gene‐based resistance, indicates some adaptation ofP. infestansto partial resistance and consequently adverse effects on the stability and durability of partial resistance to potato late blight.
Influence of spatial structure on pathogen colonization and extinction: a test using an experimental metapopulation
Authors: Thrall P. H. , Godfree R. , Burdon J. J.
Published: June 2003

The Linum marginale–Melampsora lini plant–pathogen interaction has been studied extensively with regard to its epidemiology and population genetic structure (host resistance and pathogen virulence) in a natural metapopulation. In this study, this system was used in an experimental metapopulation approach to investigate explicitly how the distance (degree of isolation) between local population patches influences disease dynamics within a growing season, as well as the genetic structure of pathogen populations through stochastic colonization and extinction processes. The experimental design centred on four replicate sets of populations, within which patches were spaced at increasingly greater distances apart. Each patch consisted of an identical set of host and pathogen genotypes, with each pathogen genotype having the ability to attack only one of four host‐resistance types. Over the 2 years of the experiment, the results showed clear ‘boom‐and‐bust’ epidemic patterns, with the strongest determinant of disease dynamics within a growing season being the identity of particular host–pathogen genotypic combinations. However, there were also significant effects of spatial structure, in that more isolated patches tended to exhibit lower levels of disease during epidemic peaks than patches that were close together. Extinction of pathogen genotypes from individual populations was positively related to the severity of disease during preceding epidemic peaks, but negatively related to the level of disease present at the final census prior to overwintering. The probability of recolonization of pathotypes into populations during the second growing season was most strongly related to the distance to the nearest neighbouring source population in which a given pathotype was present. Overall, these results highlight the importance of spatial scale in influencing the numerical and genetical dynamics of pathogen populations.
Artificial reproduction of atypical hydroa vacciniforme caused by latent Epstein–Barr virus infection
Authors: Heo E. P. , Park S. H. , Kim T.‐H.
Published: June 2003

Background Cases of hydroa vacciniforme‐like eruptions caused by latent Epstein–Barr virus (EBV) infection have been reported in Asia and Mexico, some of which progressed to lymphoproliferative disorders. The precise clinical features of the disease are not, however, clear.

Methods We performed an artificial provocation test with repeated exposures of ultraviolet A (UVA) and UVB in an 8‐year‐old Korean girl who had severe hydroa vacciniforme‐like skin eruptions on exposed areas.

Results The patient showed features of latent EBV infection serologically, and an in situ hybridization study indicated that most infiltrating mononuclear cells in the dermis were positive for EBV. After three exposures to UVA irradiation with a total dose of 90 J/cm2, erythema and vesicles appeared on the UVA‐irradiated site but not on the UVB‐irradiated site.

Conclusions Atypical hydroa vacciniforme caused by latent EBV infection could be reproduced by repeated UVA irradiation. Further study on the photo‐protection would be necessary to prevent its progression to lymphoproliferative malignancies.
Alopecia areata: psychiatric comorbidity and adjustment to illness
Authors: Ruiz‐Doblado Sergio , Carrizosa Ana , García‐Hernández Maria Jose
Published: June 2003

Background Decades ago, alopecia areata (AA) was regarded as a well‐known example of psychosomatic disease. The poor development of measurement methods and criteria for the classification of psychiatric disorders at that time was probably partly to blame for the lack of methodologic validity of some studies.

Methods We studied a random sample of 32 patients with AA (patchy form). Sociodemographic, dermatologic, and psychiatric variables were collected. Psychiatric examination was carried out by standardized interviews: Schedules for Clinical Assessment in Neuropsychiatry (SCAN), International Personality Disorders Examination (IPDE), and Psychological Adjustment to Illness Scale (PAIS), using the Research Diagnostic Criteria of the International Classification of Diseases, 10th edition, to assess the diagnosis. A descriptive and association study was performed, correlating the patient's adjustment and adaptation to the illness to various factors (linear regression techniques and analysis of variance).

Results Sixty‐six per cent of patients presented with psychiatric comorbidity, mainly adjustment disorders (F.43.2), generalized anxiety disorders (F.41.1), and depressive episodes (F.32). Overall adaptation to the illness, however, was satisfactory, showing few repercussions in family or social life, work, or sexual adjustment. Poor adjustment was associated with a dependent personality (Pearson's r = 0.66), antisocial personality (r = 0.39), generalized anxiety (P = 0.003), and depression (P = 0.02).

Conclusions There is a high psychiatric comorbidity in AA (anxiety and mood disorders), requiring systematic psychiatric evaluations of these patients. A satisfactory overall adaptation to mild/moderate forms of the disease is the norm, but adaptation and comorbidity in severe forms (totalis, universalis) are unknown. A dermatology/liaison psychiatry setting could improve the management of AA.
Periorbital edema as the presenting sign of dermatomyositis
Authors: Hall V. C. , Keeling J. H. , Davis M. D. P.
Published: June 2003

Background Periorbital edema can occur in dermatomyositis, which is characterized by symmetric macular erythema, Gottron's papules, Gottron's sign, periungual telangiectasia, heliotrope rash, and poikilodermatous macules on the shoulders, arms, or upper back (shawl sign).

Case report We report the case of an 81‐year‐old man with dramatic periorbital edema. It was not until he was hospitalized with dysphagia 6 months after developing the edema that the diagnosis of dermatomyositis was considered.

Results Laboratory tests, skin biopsy, and electromyography resulted in a diagnosis of dermatomyositis.

Conclusions Periorbital edema may appear as the presenting cutaneous manifestation of dermatomyositis.
A case of necrobiotic xanthogranuloma without paraproteinemia presenting as a solitary tumor on the thigh
Authors: Chang Sung Eun , Lee Won Sin , Lee Mi Woo , Choi Jee Ho , Sung Kyung Jeh , Moon Kee Chan , Koh Jai Kyoung
Published: June 2003

A 82‐year‐old Korean woman had had a 6‐month history of an asymptomatic, flat, hard, red to brown tumor on her right thigh. This lesion had been slowly enlarging with an advancing margin. She had noted gradually developing pain associated with necrosis and ulceration on the lesion. Examination revealed a solitary, 8 × 7.5 cm, yellow to dark red, telangiectatic tumor with multiple areas of punched out ulceration and a peripheral elevated yellowish margin on the right inner upper thigh (Fig. 1). No clinically similar lesions on the periorbital area or other sites were seen. Histologic examination revealed a massive palisading granulomatous infiltration with several layers of extensive bands of necrobiotic zone in the entire dermis and deep subcutaneous tissue (Fig. 2a). In the granulomatous infiltrate in the dermis and subcutis, many various‐shaped, some bizarre, angulated, foreign‐body type multinucleated giant cells, many Touton giant cells, and a few Langhans giant cells were found to be scattered (Fig. 2b). There were numerous xanthomatized histiocytes. Dense infiltration of lymphoplasma cells was seen in the periphery of the granuloma and perivascularly. Conspicuous granulomatous panniculitis composed of lymphoplasma cells, polymorphonuclear cells, foam cells, and Touton and foreign‐body giant cells was also seen. However, cholesterol clefts and lymphoid follicles were not seen. Subcutaneous septae were widened by necrobiotic change and fibrosis with thrombosed large vessels. Gram, Gomeri‐methenamine silver and acid‐fast stains were negative. The necrobiotic areas were positive to alcian blue. Laboratory investigation revealed elevated white blood cell counts, anemia and elevated erythrocyte sedimentation rate. The following parameters were within the normal range: lipids, glucose, renal and liver function tests, serum complements, serum immunoglobulins, cryoglobulins and antinuclear antibodies. The findings of chest X‐ray, skull X‐ray and ectorcardiography were normal. Serum electrophoresis and serum immunoelectrophoresis revealed no abnormality. The patient was diagnosed as having necrobiotic xanthogranuloma without paraproteinemia. She was treated with oral steroid (0.5–0.6 mg/kg) and NSAIDS for 1 month with partial improvement of pain and the lesion ceased to enlarge. In the following 1 year of follow‐up, with only intermittent NSAIDS, her lesion did not progress and there were no signs of systemic involvement or new skin lesions.

(a) A solitary, red to brown plaque with multiple ulcerations and a peripheral elevated yellowish margin on the inner upper thigh

image

(a) A dermal and subcutaneous massive xanthogranulomatous infiltrate with zonal necrobiosis of collagen (× 20). (b) Prominent infiltrate of xanthomatized histiocytes and giant cells with perivascular lymphoplasma cells (H&E, × 100)

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Spectrum of idiopathic photodermatoses in a Mediterranean country
Authors: Stratigos Alexander J. , Antoniou Christina , Papathanakou Evangelia , Daboudi Maria , Tranaka Konstantina , Tsara Konstantina , Katsambas Andreas D.
Published: June 2003

Background  Idiopathic photodermatoses are considered to be common disorders in the population of northern latitude countries, presumably because of the dominance of more “sun‐sensitive” individuals with a light‐skinned complexion. The incidence of these disorders in the Mediterranean or tropical countries is often under‐appreciated because of the higher degree of perennial presence of sunlight and the prevalence of darker skin‐type individuals who are seemingly more resistant to the development of sun sensitivity.

Methods  We performed a retrospective, chart‐based review of all patients who were diagnosed with idiopathic photodermatoses at a photodermatology referral center in Athens, Greece, during a period of 10 years. Our aim was to assess the pattern of idiopathic photosensitivity disorders in a Mediterranean country and to determine their epidemiological, clinical, and photobiological profile.

Results  A total of 310 patients were referred to our center with symptoms of photosensitivity. One hundred and forty‐six patients (47.0%) were diagnosed with an idiopathic photosensitivity disorder by means of history, clinical examination, biochemical screening, histology, and phototesting. The most prevalent disorder was polymorphous light eruption, which was diagnosed in 95 patients (65.0%) of our cohort. Chronic actinic dermatitis occurred in 15 patients (10.2%), solar urticaria in 26 patients (17.8%), actinic prurigo in three patients (2.0%), hydroa vacciniforme in one patient (0.6%) and juvenile spring eruption in six patients (4.1%).

Conclusions  Compared with the results of other studies, the prevalence of idiopathic photodermatoses appears to have a similar trend to that of higher latitude countries. Distinct features in our series include the higher incidence of idiopathic photosensitivity in patients with a fair‐skinned complexion (skin types II–III) and the frequent appearance of photo‐induced eruptions during sunny weather breaks in the winter period.
The role of gabapentin in treating diseases with cutaneous manifestations and pain
Authors: Scheinfeld Noah
Published: June 2003

Background Gabapentin was first approved by the FDA in 1993 as an add‐on treatment for partial epileptic seizures. In May of 2002, it was approved as treatment for post‐herpetic neuralgia by the Food and Drug Adminstration. It appears to be a promising agent in the treatment of pain, alterations of sensation and pruritus associated with dermatological disease, but no review of these uses exists.

Methods Medline and Google searches were performed for the words “Gabapentin” and “Neurontin.” The articles found were reviewed. Article identified that contained references to the treatment of skin disease and neuropathic pain were examined and their contents surveyed.

Results Approximately 1200 articles were located n Medline that referred to Garbapentin or Neurontin. Over 150 articles reviewed its use for neuropathic pain, neuritis or neuralgia of various sorts. Approximately 20 articles reviewed its use for a variety of dermatological conditions or diseases with dermatological manifestions that included: pain control associated with wound dressing changes, erythromelagia, piloleiomyoma related pain, brachioradial pruritus, Glossodynia, vulvodynia, and reflex sympathetic dystrophy. Over 100 articles that related to Gabapentin side effects were reviewed.

Conclusions Gabapentin is a very promising medication in the treatment of post‐herpetic neuralgia and pain. Because dermatological patients suffer pain from painful tumors, after surgery, in conjunction with neuropathic ulcers, during dressing changes involving serious medical conditions, its applications seem manifold. Future studies must assess its role in the treatment of pruritus and other dermatological conditions involving pain or alteration of sensation.
Herpetic whitlow during isotretinoin therapy
Authors: Stetson Cloyce L. , Butler David F. , Rapini Ronald P.
Published: June 2003

Isotretinoin is an extremely valuable drug that is occasionally associated with well‐known mucocutaneous side‐effects, including cheilitis, retinoid dermatitis, palmoplantar desquamation, and photosensitivity. Paronychia has been reported rarely: only two prior cases of herpes simplex infections associated with isotretinoin have been previously reported. We present the first known case of herpetic paronychia occurring in an atopic patient while on isotretinoin therapy for acne.
Pathogenesis of Potato Gangrene Caused by Phoma exigua var. foveata. I. Location of Phosphatase Activity in Diseased Tuber Tissue
Authors: Giebel J. , Dopierała U.
Published: June 2003

The nitrocellulose blotting method was adapted for locating phosphatase activities in gangrene‐diseased tuber tissue. Adenine and glucose phosphates were used as enzyme substrates. A strong dephosphorylation of high‐energy phosphates took place in the UV‐fluorescent tissue adjacent to dry rots caused by Phoma exigua var. foveata, but the enzyme remained at a low activity in the other areas of the diseased tuber. Phosphatases were probably induced by P. exigua var. foveata, and intense dephosphorylation of high‐energy compounds leads to the death of potato tuber tissue.
Light and Electron Microscopy of the Compatible Interaction Between Arabidopsis and the Downy Mildew Pathogen Peronospora parasitica
Authors: Soylu E. M. , Soylu S.
Published: June 2003

In this study, we focused on compatible interactions between Peronospora parasitica isolate Emoy‐2 and wild‐type (Oy‐0) and mutant (Ws‐eds1) Arabidopsis thaliana accessions by using light and transmission electron microscopy (TEM). Light microscopy of compatible interactions revealed that conidia germinated and penetrated through the anticlinal cell walls of two epidermal cells. Rapid spreading of the hyphal growth with formation of numerous haustoria within the mesophyll cells was subsequently followed by profuse sporulation in the absence of host cell necrosis on both wild‐type and mutant accessions. TEM observations revealed that coenocytic intercellular hyphae ramified and spread intercellularly throughout the host tissue forming several haustoria in host mesophyll cells. Intracellular haustoria were lobed with the diameter of 6–7 μm. Each haustorium was connected to intercellular hyphae in the absence of apparent haustorial neck. The cytoplasm of the haustorium included the organelles characteristic of the pathogen. Callose‐like deposits were frequently observed at sites of penetration around the proximal region of the haustorial neck. Apart from a few callose ensheatments, no obvious response was observed in host cells following formation of haustoria. Most of mesophyll cells contained normal haustoria and the host cytoplasm displayed a high degree of structural integrity. Absence of host cell wall alteration and cell death in penetrated host cell of both accessions suggest that the pathogen exerts considerable control over basic cellular processes and in this respect, response to this biotroph oomycete differs considerably from responses to other pathogens such as necrotrophs.
Nested PCR Assays for Detection of Monilinia fructicola in Stone Fruit Orchards and Botryosphaeria dothidea from Pistachios in California
Authors: Ma Z. , Luo Y. , Michailides T. J.
Published: June 2003

Nested polymerase chain reaction (PCR) assays were developed based on microsatellite regions for detection of Monilinia fructicola, the causal agent of brown rot of stone fruits, and Botryosphaeria dothidea, the causal agent of panicle and shoot blight of pistachio. The nested PCR primers specific to M. fructicola were developed based upon the sequence of a species‐specific DNA fragment amplified by microsatellite primer M13. The external and internal primer pairs EMfF + EMfR and IMfF + IMfR amplified a 571‐ and a 468‐bp fragment, respectively, from M. fructicola, but not from any other fungal species present in stone fruit orchards. The nested PCR primer pairs specific to B. dothidea were developed based upon the sequence of a species‐specific 1330‐bp DNA fragment amplified by microsatellite primer T3B. The external and internal primer pairs EBdF + EBdR and IBdF + IBdR amplified a 701‐ and a 627‐bp fragment, respectively, from B. dothidea, but not from any other fungal species associated with pistachio. The nested PCR assays were sensitive enough to detect the specific fragments in 1 fg of M. fructicola or B. dothidea DNA or in the DNA from only two conidia of M. fructicola or B. dothidea. The nested PCR assays could detect small numbers of M. fructicola conidia caught on spore‐trap tapes and detect visible infections of B. dothidea in pistachio tissues. Microsatellite regions with high numbers of copies are widely dispersed in eukaryotic genomes. The results of this study indicate that microsatellite regions could be useful in developing highly sensitive PCR detection systems for phytopathogenic fungi.
First Report ofAlternariaLeaf Spot on Gerbera (Gerbera jamesoniiH. Bolux ex J. D. Hook) in Bulgaria
Authors: Mirkova E. , Konstantinova P.
Published: June 2003

Alternarialeaf spots of gerbera (Gerbera jamesoniiH. Bolus ex J. D. Hook) were observed on plants from different greenhouses on commercial plants in Bulgaria. The symptoms of the disease on the leaves were characterized by the development of brown, small, scattered dots, which gradually enlarged and coalesced to form large, oval, circular or irregular, brown to black lesions with concentric rings. Affected plants showed lower vitality, suppressed development and fewer, smaller, distorted in shape flowers.Alternariaisolates, obtained from infected leaf tissues were grown in pure culture and the morphological characteristics of the colony and sporulation apparatus were determined. DNA, extracted from the fungal isolates was subjected to polymerase chain reaction (PCR) with primers ITS1/ITS4, amplifying the internal transcribed spacer (ITS) regions. The resulting products were sequenced and compared for homology with other species in the GeneBank. The isolates showed 94% homology of the ITS region with eitherAlternaria alternata,A. arborescens,A. tenuissima,A. longipes,A. liniorA. smyrnii. None of the studied isolates was amplified with theA. alternataspecific primers AAF2/AAR3, indicating that they are pathogenic varieties of it or belong to another species. Pathogenicity tests on 10 gerbera cultivars revealed that all of them were susceptible toAlternarialeaf spot. Additional tests on nine other crops (Solanum lycopersicum,Calendula officinalis,Capsicum annuum,Celosia argantea,Pelargoniumspp.,Petunia hybrida,Nicotiana tabacum,Cucurbita moscataandRaphanus sativusvar.radicina) and on tomato or pepper fruits, potato tubers and carrot roots also indicated that all tested plant species were potential hosts of the disease. This is the first report of highly virulent isolates ofAlternariaspp. in Bulgaria that cause leaf spots on gerbera in greenhouses.
Summer Epidemics of Apple Scab: The Relationship between Measurements and their Implications for the Development of Predictive Models and Threshold Levels under Different Disease Control Regimes
Authors: Holb I. J. , Heijne B. , Jeger M. J.
Published: June 2003

A 2‐year study on epidemic progress of apple scab was conducted at Randwijk, the Netherlands, in 1998 and 1999. The summer epidemic caused by conidia was studied instead of the well‐described spring season epidemic originating from ascospores. The aim was to investigate relationships between disease measurements, i.e. disease incidence and severity measures of apple scab, and their implications for the development of predictive models and threshold levels. The study characterized good relationships between the measurements on cultivar Jonagold using regression analyses in three disease control regimes (untreated, organic and integrated). For fruit quality prediction, the relationship between fruit incidence (If) and leaf incidence (Il) in the organic control regime was given by If = 1.966 + 0.402 × (Il) (R2 = 0.92). As a result of low level of disease in the integrated control regime, shoot incidence (Is), with higher values than leaf incidence, was better suited for prediction. The relationship was given by If = −0.162 + 0.028 × (Is) (R2 = 0.91). For the integrated control regime, disease threshold levels were constructed for timing of the final fungicide application. If an apple grower wants to keep fruit infection under 1% incidence (harvest scab threshold), the timing of the final fungicide application (action threshold) should correspond to 4% shoot scab incidence at the beginning of August. The results are compared with similar studies and their biological interpretation is discussed.
Production of a Monoclonal Antibody to Sugarcane mosaic virus and its Application for Virus Detection in China
Authors: Jiang J. X. , Chen Z. X. , Zhou X. P.
Published: June 2003

Three monoclonal antibodies (MAbs) were raised against the virion protein of Sugarcane mosaic virus Zhejiang isolate (SCMV‐ZJ). All three MAbs, which belong to the immunoglobulin (IgG1) subclass, reacted with isolates of SCMV but not with seven other viruses tested by indirect antigen‐coating plate enzyme‐linked immunosorbent assay (ELISA) (ACP‐ELISA). MAb 2B5 was used in indirect ACP‐ELISA for the detection of SCMV in maize leaf samples showing dwarf mosaic symptoms, and all 176 were found to be infected. Results of ACP‐ELISA with MAb 2B5 correlated well with those obtained by reverse transcriptase‐polymerase chain reaction (RT‐PCR) using the same tissues. This demonstrates that MAb 2B5 can be used to detect isolates of SCMV in field samples and that the virus is possibly the most common cause of maize dwarf mosaic disease in different parts of China.
WANTED: TRAINEES FOR RURAL PRACTICE
Authors: Topps David , Rourke James , Newbery Peter
Published: June 2003

ABSTRACT: To address the increasing need for rural health practitioners, Canada is trying various methods of medical education, including community based residency streams, additional skills training and teamwork models. This paper discusses some of the factors that may affect the effectiveness of these methods.
STRADDLING THE PATHWAY FROM PAEDIATRICIAN TO MAINSTREAM HEALTH CARE: TRANSITION ISSUES EXPERIENCED IN DISABILITY CARE
Authors: O'Connell Bev , Bailey Susan , Pearce Julian
Published: June 2003

Objective: To identify the strengths and limitations of health care and related services provided to young adults with a disability during the period of transition from the care of a paediatrician to the mainstream health system.

Design: A descriptive design was used to address the study objectives.

Setting: Barwon and south‐western region of Victoria.

Subjects: Twelve focus group discussions, with young adults with a disability, carers of young adults with a disability and health care service providers. Each focus group involved eight to 10 participants.

Results: The findings revealed a number of problems with the transition period. All participants acknowledged the supportive, coordinating role of the paediatrician. In the absence of this type of role, carers felt they lacked the knowledge and support to manage the adolescent with a disability. Communication problems between all service providers were identified as being problematical. The general lack of continuity of care between providers made it difficult for individuals to negotiate the transition period and increased the burden of care on carers.

Conclusion: There is a need for policy makers to address these transition problems and develop appropriate services that improve the situation for young adults with a disability and their carers.

What is already known: It is well documented that the transition period from paediatrician to adult health care services is problematic for the young adult with a disability and their carer. The difficulties experienced are attributed to poor communication between service providers and a lack of continuity of care.

What does this study add: This study provides insights from a number of different consumer and health care professionals’ perspectives. The findings identify service delivery gaps and a need to develop health care services that could assist the young adult with the disability negotiate this transition from the paediatric services to mainstream health care services in rural and regional settings in Victoria.
RURAL ORIGIN MEDICAL STUDENTS: HOW DO THEY COPE WITH THE MEDICAL SCHOOL ENVIRONMENT?
Authors: Durkin Shane R. , Bascomb Angela , Turnbull Deborah , Marley John
Published: June 2003

Australia suffers from a well documented shortage of rural medical practitioners. In an attempt to increase recruitment, it has emerged that rural origin medical students are more than twice as likely as their urban colleagues to become rural practitioners. This has led to a wide range of programs aimed at increasing the number of rural students who apply for and gain entry into medical school. But how do rural students cope with the medical school environment? This paper was based on the results of a survey of senior medical students and looked at how rural students’ fare with the medical school environment compared to their urban counterparts. It was concluded that government initiatives currently supporting rural medical students must be continued into the future and continuously evaluated to ensure that rural students have a positive learning experience in preparation for future rural practice.
A conceptual framework of functional capacity evaluation for occupational therapy in work rehabilitation
Authors: Gibson Libby , Strong Jenny
Published: May 2003

Functional capacity evaluation (FCE) is commonly used in work rehabilitation to assess the capacity of the injured worker for return to work. Occupational therapists are major providers of FCE, especially in Australia. Despite a history of involvement in the functional assessment of clients for work, occupational therapy has few theoretical models for work assessment in general, and for FCE in particular. This may account for some of the confusion that exists about the conceptual basis of FCE in occupational therapy practice. This paper presents a framework for FCE that parallels occupational therapy's occupational performance model and the World Health Organisation's International Classification of Functioning, Disability and Health. The framework is used to clarify some of the confusions that exist in FCE research and practice, particularly the issue of measuring a client's function versus impairment. A redefinition of FCE for occupational therapy practice in the work assessment continuum is presented that supports occupational therapy practice and research in the area.
A prospective study of patient identified unmet activity of daily living needs among cancer patients at a comprehensive cancer care centre
Authors: Taylor Karen , Currow David
Published: May 2003

Cancer, as a chronic illness, demands a new focus in physical and emotional support. Thus, an assessment of activities of daily living needs among cancer patients was completed. A 1‐week, cross‐sectional survey of patients was undertaken, by using the Modified Barthel Index, the Eastern Co‐operative Oncology Group performance status, a Modified Instrumental Activities of Daily Living Scale and a screening tool. As functional status declined, the number of unmet needs per patient increased. At least one‐third of patients who would benefit from assessment were not referred. Without simple screening tools, the needs of this population are not always being recognised or met. Patient identified needs, when analysed by functional level and treatment intent, challenge existing assumptions of service provision. In conclusion, there is an unmet need in this cancer population. By using the Screening Tool on referral, and with each change in level of function (as measured by the Eastern Co‐operative Oncology Group), it would help identify patients who may benefit more from occupational therapy assessment.
Differences in activities of daily living motor skills of persons with and without Alzheimer's disease
Authors: Oakley Frances , Duran Leslie , Fisher Anne , Merritt Brenda
Published: May 2003

The purpose of this descriptive comparison study is to determine if persons with dementia of the Alzheimer's type differ from well older controls in the motor skills that affect the quality of performance of activities of daily living, and if so, to identify those specific activities of daily living motor skills that are retained or lost. The Assessment of Motor and Process Skills was administered to a proportionally matched sample of 567 persons with dementia of the Alzheimer's type and 378 community‐living non‐disabled controls, all of whom were 60 years or older. We found significant differences in mean activities of daily living motor ability between non‐disabled controls, higher functioning participants with dementia of the Alzheimer's type, and lower functioning participants with dementia of the Alzhemier's type. Thus, diminished motor skills appear to affect the quality of activities of daily living task performance of persons with dementia of the Alzhemier's type, even those who are higher functioning. These findings suggest that motor skills may need to be addressed in intervention planning for persons with dementia of the Alzheimer's type.
A psychospiritual integration frame of reference for occupational therapy. Part 1: Conceptual foundations
Authors: Kang Chris
Published: May 2003

This paper introduces a new clinical practice framework — the psychospiritual integration frame of reference. It opens with a broad discussion on spirituality as articulated within occupational therapy and occupational science literature, followed by a brief introduction into framework's paradigm and interdisciplinary knowledge base. A general description of the frame of reference's major constructs and principles, as well as theoretical arguments concerning order, disorder, and the model's dynamics, are presented and discussed. The psychospiritual integration frame of reference is offered as a contribution to the existing collection of practice frameworks drawn upon by occupational therapists in their day‐to‐day work.
Excitotoxic lesions of the prelimbic‐infralimbic areas of the rodent prefrontal cortex disrupt motor preparatory processes
Authors: Risterucci Céline , Terramorsi Denise , Nieoullon André , Amalric Marianne
Published: May 2003

The medial prefrontal cortex (mPFC) is involved in a variety of cognitive and emotional processes; in rodents its implication in motor planning is less known, however. We therefore investigated how the mPFC contributes to the information processes involved in the execution of a reaction time task in rats. Subjects were trained to rapidly release a lever at the onset of a cue light, which was presented after an unpredictable period of variable duration (500, 750, 1000 and 1250 ms). Excitotoxic lesions of the whole mPFC or two mPFC subregions [e.g. the dorsal anterior cingulate and the prelimbic‐infralimbic (PL‐IL) areas] were achieved by intracerebral infusions of ibotenic acid (9.4 µg/µL) at different volumes. Extensive mPFC lesions produced increased premature responding and disrupted motor readiness, e.g. the distribution of preparatory patterns during the variable preparatory periods. The deficits lasted for 3 weeks and could be reinstated 2 months after the lesion by varying the duration of the preparatory periods to increase time uncertainty. Furthermore, lesions restricted to the PL‐IL cortex areas reproduced all the deficits of mPFC lesions, whereas pregenual anterior cingulate cortex lesions had no effect. The results emphasize a critical role of the rat PL‐IL region in motor preparatory processes. Hence, discrete lesions of this area reproduce some deficits such as impairment of time estimation and disinhibitory behaviours observed in humans with frontal hypoactivity.