bluuebunny/crossref_metadata_2025 huggingface dataset:
Dengue virus infection rate in field populations of female Aedes aegypti and Aedes albopictus in Singapore
Authors: Chung Youne Kow , Pang Fung Yin
Published: March 2003

We developed a single‐step reverse transcription‐polymerase chain reaction (RT‐PCR) followed by a seminested PCR using an upstream consensus primer and four type‐specific primers within the non‐structural protein gene (NS3) of dengue viruses to type dengue viruses in field populations of female Aedes mosquitoes. This yielded diagnostic fragments of 169, 362, 265 and 426 base pairs for dengue virus types 1, 2, 3 and 4, respectively. From 1997 to 2000, 54 (6.9%) of 781 Aedes aegypti and 67 (2.9%) of 2256 Aedes albopictus screened were positive for dengue viruses, with a declining trend. The most common dengue virus type detected in the Aedes mosquitoes was dengue‐1. Details on the change of one serotype to another in the mosquito population over three consecutive years are discussed.
Malaria control reinvented: health sector reform and strategy development in Colombia
Authors: Kroeger Axel , Ordoñez‐Gonzalez José , Aviña Ana Isabel
Published: March 2003

The consequences of health sector reforms on control of malaria were analysed using Colombia as an example. One of the most complex health sector reform programmes in Latin America took place in the 1990s; it included transferring the vertical vector‐borne disease control (VBDC) programme into health systems at state and district levels. A series of studies was undertaken in 1998–2000 at the national level (Ministry of Health Study), at the state level (Departamento Study) and at the health district level (District Study) using formal and informal interviews among control staff and document analysis as data collection tools. A government‐financed national training programme for VBDC staff – which included direct observation of control operations – was also used to analyse health workers' performance in the postreform period (longitudinal study). The results showed that some shortcomings of the old vertical system, such as the negative aspects of trade union activity, have not been overcome while some positive aspects of the old system, such as capacity building, operational planning and supervision have been lost. This has contributed to a decrease in control activity which, in turn, has been associated with more malaria cases. Malaria control had to be reinvented at a much larger scale than anticipated by the reformers caused by a whole series of problems: complex financing of public health interventions in the new system, massive staff reductions, the difficulty of gaining access to district and state budgets, redefining entire organizations and – in addition to the reforms – introducing alternative strategies based on insecticide‐treated materials and the growth of areas of general insecurity in many parts of Colombia itself. However, positive signs in the transformed system include: the strengthening of central control staff (albeit insufficient in numbers) when transferred from the Ministry of Health to the National Institute of Health, the opportunities offered by the Basic Health Plan (PAB) for new planning initiatives and intersectoral co‐operation and the integration of malaria diagnosis and treatment into the general health services (associated with a decrease of malaria mortality). The potentials of the new system have not yet been fully exploited: capacity building, communication and management skills need to be improved and it require guidance from the national level.
Review: HIV infection and tropical parasitic diseases – deleterious interactions in both directions?
Authors: Harms Gundel , Feldmeier Hermann
Published: March 2003

HIV and parasitic infections interact and affect each other mutually. Whereas HIV infection may alter the natural history of parasitic diseases, impede rapid diagnosis or reduce the efficacy of antiparasitic treatment, parasitoses may facilitate the infection with HIV as well as the progression from asymptomatic infection to AIDS. We review data on known interactions for malaria, leishmaniasis, Human African Trypanosomiasis, Chagas' disease, onchocerciasis, lymphatic filariasis, schistosomiasis and intestinal helminthiases. The common immunopathogenetic basis for the deleterious effects parasitic diseases may have on the natural history of HIV infection seems to be a particular type of chronic immune activation and a preferential activation of the T helper (Th)2 type of help. Control of parasitic diseases should complement the tools currently used in combating the HIV pandemic.
Maîtriser un espace sanitaire cohérent et performant dans les villes d'Afrique subsaharienne: le district de santéà l'épreuve
Authors: Grodos Daniel , Tonglet René
Published: March 2003

situation du problème 

La santé dans les villes est un thème d'actualité en santé publique mais l'organisation des systèmes de santé urbains n'est pas l'objet d'une attention suffisante.

objectif  Analyser les problèmes posés par l'organisation des systèmes de santé dans les villes d'Afrique subsaharienne et proposer un outil pour résoudre ces problèmes.

méthode  Exposé d'une thèse basée sur une revue de l'expérience internationale en matière d'organisation des services et soins de santé en ville et sur plusieurs études de cas.

résultats  Nous défendons l'idée que le modèle du district de santé doit être réexaminé dans la perspective de la maîtrise d'un espace sanitaire cohérent et performant en ville. Nous examinons ensuite les menaces particulières qui pèsent sur le district de santé dans le contexte urbain et nous soutenons la thèse que la prise au sérieux de celles‐ci impose de procéder à certaines adaptations du modèle de district de santé mais n'oblige aucunement à l'abandonner. Nous précisons enfin dans quelle mesure cette option pour un système local de santé intégré fondé sur la notion de district de santé se distingue d'autres options plus actuelles, comme la réforme du secteur de la santé préconisée par la Banque mondiale, les approches sectorielles du financement durable des dépenses de santé, les approches dites émergentes basées sur la promotion de la santé et les stratégies de survie des acteurs dans un contexte défavorable.

conclusion  Une plus grande maîtrise de l'espace sanitaire dans les villes d'Afrique subsaharienne peut être acquise en structurant le système de santé sur la base des zones de responsabilité que sont les districts sanitaires, à condition d'utiliser le modèle de district avec un recul critique suffisant et de faire l'effort de préciser les éléments permettant de juger la fonctionnalité du district de santé dans le contexte urbain. La mise en œuvre de cette stratégie nécessite avant tout de prendre des décisions à caractère politique et n'appelle qu'accessoirement des solutions techniques. Il s'agit, entre autres, de légitimer une autorité sanitaire urbaine coordonnant les divers acteurs et disposant des moyens matériels et humains adéquats, de redéfinir le rôle des grands établissements hospitaliers, et de réguler la privatisation du secteur de la santé.
Too poor to pay: charging for insecticide‐treated bednets in highland Kenya
Authors: Guyatt Helen L. , Ochola Sam A. , Snow Robert W.
Published: March 2003

WHO has proposed malaria control as a means to alleviate poverty. One of its targets includes a 30‐fold increase in insecticide‐treated nets (ITNs) in the next 5 years. How this service will be financed remains unclear. In July 2000, 390 homesteads in rural highland Kenya were interviewed on their willingness to pay for ITNs. The costs to a household of protecting themselves with ITNs were compared with current household expenditure. Homesteads expressed a willingness to pay for ITNs, but the amounts offered were not sufficient to cover the costs of providing this service without donor support to meet the difference. Furthermore, as most household expenditure was allocated to basic needs these interventions were ‘unaffordable’. The cost of protecting a household with ITNs would be equivalent to sending three children to primary school for a year. The aspiration by poor rural homesteads to protect themselves with ITNs is not compatible with their ability to pay. One option to have an immediate equitable impact on ITN coverage and break the cycle between malaria and poverty is to provide this service free of charge.
Combination of eflornithine and melarsoprol for melarsoprol‐resistant Gambian trypanosomiasis
Authors: Mpia Bokelo , Pépin Jacques
Published: March 2003

Objective  To evaluate the efficacy and toxicity of a combination of eflornithine and melarsoprol among relapsing cases of Gambian trypanosomiasis.

Methods  Forty‐two late‐stage Trypanosoma brucei gambiense trypanosomiasis patients relapsing after initial treatment with melarsoprol were treated with a sequential combination of intravenous eflornithine (100 mg/kg every 6 h for 4 days) followed by three daily injections of melarsoprol (3.6 mg/kg, up to 180 mg). They were then followed‐up for 24 months.

Results  Two (4.8%) patients died during treatment. Of the 40 surviving patients, two had a treatment failure, 13 and 19 months after having received the combination therapy. By Kaplan–Meier analysis, the 2‐year probability of cure was 93.3% (95% confidence interval: 84.3–100%).

Conclusion  This sequential combination has an efficacy and a toxicity similar to a 7‐day course of eflornithine monotherapy, but is easier to administer. Whether such therapeutic success corresponds tosynergism between eflornithine and melarsoprol, or merely means that 4 days of eflornithine monotherapy suffices for such patients, will need to be determined in a comparative trial.
Short communication: Point mutations in the dihydrofolate reductase and dihydropteroate synthase genes of Plasmodium falciparum isolates from Colombia
Authors: Schmider Nadja , Peyerl‐Hoffmann Gaby , Restrepo Marcos , Jelinek Tomas
Published: March 2003

Point mutations in the dihydrofolate reductase (DHFR) and dihydropteroate synthase (DHPS) genes of Plasmodium falciparum can lead to an increasing resistance of P. falciparum to pyrimethamine/sulphadoxine. We examined the prevalence of these mutations in 36 samples from Colombia. Analysed by polymerase chain reaction (PCR) for infection with P. falciparum, 25 (69%) tested positive. These positive isolates were tested further for point mutations in the genes of DHFR (codons 16, 51, 59, 108 and 164) and DHPS (codons 436, 437, 540, 581 and 613) by nested PCR and following mutation‐specific restriction enzyme digestion. Gene mutations occurred in both the DHFR and DHPS gene of the Colombian isolates, suggesting that resistance to antifolate drugs exists or may develop soon in Colombia.
Development of a new sensitive and efficient multiplex polymerase chain reaction (PCR) for identification and differentiation of different mycobacterial species
Authors: Bhattacharya Basudev , Karak Kalpana , Ghosal Alok Gopal , Roy Atanu , Das Shyamal , Dandapat Premanshu , Khetawat Dimple , Mondal Dibya Kanti , Bhattacharya Sujit , Chakrabarti Sekhar
Published: March 2003

For early detection and species differentiation of mycobacteria, polymerase chain reaction (PCR) techniques are currently in wide use. However, individual techniques using amplification of different targets with appropriate primers still have some limitations, which have to be overcome. The ideal technique would use DNA sequences which should be present in all mycobacteria and absent in others and would be able to discriminate one species from the other, as non‐tuberculous mycobacteria (NTM) are on rise in terms of frequency of detection. We developed a multiplex PCR based on amplification of 165, 365 and 541 bp target fragments of unrelated genes, hsp 65 coding for 65 kDa antigen, dnaJ gene of mycobacteria and insertion element IS 6110 of Mycobacterium tuberculosis, respectively. This multiplex PCR was tested over 5 years from 1996 to 2001 with 411 clinical specimens from suspected cases of tuberculosis and mycobacterioses and compared with standard laboratory techniques. The multiplex PCR was positive for 379 cases compared with 280 cases by standard techniques (P < 0.0001). It could distinguish between strains of the M. tuberculosis complex and NTM; the results are comparable with standard techniques. Thus the multiplex PCR can be useful in early detection, species differentiation and epidemiology.
A hereditary disorder of cornification and multiple congenital defects in five Rottweiler dogs
Authors: LEWIS  , MESSINGER  , GINN  , FORD
Published: March 2003

The clinical, biochemical, histological, or ultrastructural abnormalities of five related female Rottweiler dogs with a hereditary disorder of cornification are reported. Three of the five dogs also had multiple noncutaneous congenital defects. Cutaneous abnormalities included generalized, hyperkeratotic, variably pigmented plaques, which in one dog were distributed along Blaschko's lines. Moderate to severe parakeratosis involving the follicular infundibula and ostia and focal orthokeratosis with variable vacuolation of spinous cells was observed on histopathologic examination of all skin specimens. Supplementation with oral zinc in two dogs and vitamin A alcohol and calcitriol in one dog did not result in clinical or histological improvement of the hyperkeratotic lesions. This disorder of cornification in dogs is similar to human disorders of cornification that follow the lines of Blaschko. Blaschko's lines follow a V‐shape over the spine, an S‐shape on the abdomen, and an axial distribution on the limbs. No related male dogs were affected, suggesting an X‐linked dominant mode of inheritance. Many features of this hereditary DOC correspond to the human condition CHILD syndrome.
Apoptosis in selected skin diseases
Authors: Noli  , Von Tscharner  , Suter
Published: March 2003

Ten cases each of lupus erythematosus (discoid or systemic, LE), pemphigus foliaceus (PF) and erythema multiforme (EM), seven cases of toxic epidermal necrolysis (TEN) and two specimens of normal canine skin have been evaluated for the presence of apoptotic cells by immunohistochemistry using a commercially available in situ apoptosis detection kit (ApopTag, Oncor). In normal skin sections cells located in the centre of sebaceous glands and in catagen hair follicles were stained. In TEN no epidermal cell was positive, whereas in LE scattered basal and low suprabasal cells stained, and in EM single suprabasal epidermal cells stained. In PF acantholytic cells were predominantly negative, but there were single positive suprabasal cells in the neighbourhood of the acantholytic foci. Satellitosis, phagocytosis of apoptotic material and apoptosis of dermal inflammatory cells were also observed. The special staining procedure, if compared with light microscopic observation of haematoxylin/eosin specimens, resulted in a reliable tool for identification of apoptotic cells in normal and lesional skin. Data on the presence or absence of apoptotic cells in the dermatopathies examined may cast a new light on the pathogenesis of these diseases.
Delayed hypersensitivity reactions to sulphonamides: syndromes, pathogenesis and management
Authors: Trepanier L.A.
Published: March 2003

Sulphonamide antibiotics are a commonly used, and important, group of antibiotics in veterinary dermatology. However, many of the commonly used sulphonamides such as sulphamethoxazole, sulpha‐diazine, or sulphasalazine are associated with idiosyncratic drug reactions in dogs. This paper will review the clinical syndromes, pathogenesis of sulphonamide hypersensitivity reactions and current methods for predicting these occurrences.
Rapid identification of tissue micro‐organisms in skin biopsy specimens from domestic animals using polyclonal BCG antibody
Authors: Bonenberger T.E. , Ihrke P.J. , Naydan D.K. , Affolter V.K.
Published: March 2003

Immunostaining with polyclonal anti‐Mycobacterium bovis (BCG) was evaluated as a single screen‐ing method for the histological identification of micro‐organisms in skin biopsy specimens from various veterinary species. Confirmed archival cases infected with Mycobacteria, Nocardia, Actinobacillus, Actinomyces, Streptococcus/Staphylococcus, Dermatophilus, spirochetes, Blastomyces, Coccidioides, Crypto‐coccus, Histoplasma, dermatophytes, Malassezia, Sporothrix, Leishmania, Pythium, phaeohyphomycetes and Prototheca organisms were selected. A total of 70 skin biopsy specimens from the dog, cat, horse, ox and llama were evaluated. The anti‐BCG immunostain labelled bacteria and fungi with high sensitivity and minimal background staining but did not label spirochetes and protozoa (Leishmania). Differences were not noted between veterinary species. The results indicate that immunostaining with polyclonal anti‐BCG is a suitable screening technique for the rapid identification of most common bacterial and fungal organisms in paraffin‐embedded specimens. Also, mycobacterial and nocardial organisms were identified more readily with the anti‐BCG immunostain in comparison to the histochemical stains.
PCR‐based detection ofPythiumandLagenidiumDNA in frozen and ethanol‐fixed animal tissues
Authors: Znajda Nadine R. , Grooters Amy M. , Marsella Rosanna
Published: March 2003

Abstract The purpose of this study was to evaluate the application of previously describedPythium insidiosum‐andLagenidium‐specific nested PCR assays to the detection of oomycete DNA in animal tissues. DNA was extracted from 15 frozen and 10 ethanol‐fixed tissues obtained from six animals with pythiosis, five animals with lagenidiosis, one animal with nonoomycotic skin disease and two animals without skin disease. First‐round PCR, which utilized universal fungal primers ITS1 and ITS2P, amplified a single product of the expected size for each of theP. insidiosum‐andLagenidium‐infected tissues, but not for tissues obtained from animals without fungal disease. Second‐round PCR using theP. insidiosum‐specific primers PI1 and PI2 produced a single 105‐bp product for theP. insidiosum‐infected tissues, but not for any of the other tissues. Second‐round PCR using theLagenidium‐specific primers LAG1 and LAG2 produced a single 76‐bp product for theLagenidium‐infected tissues, but not for any of the other tissues.
Orobanche aegyptiaca control in tomato fields with sulfonylurea herbicides
Authors: HERSHENHORN  , GOLDWASSER  , PLAKHINE  , ALI  , BLUMENFELD  , BUCSBAUM  , HERZLINGER  , GOLAN  , CHILF  , EIZENBERG  , DOR  , KLEIFELD
Published: March 2003

Field experiments were conducted from 1994 to 1997 at two locations to study the effectiveness of chlorsulfuron and triasulfuron applied through different irrigation methods (chemigation) for control of Orobanche aegyptiaca Pers. in tomato (Lycopersicon esculentum Mill). Three split applications of chlorsulfuron at 2.5 g a.i. ha−1 and of triasulfuron at 7.5 g a.i. ha−1, through conventional sprinkler irrigation systems, 10–14 days apart followed immediately by sprinkling with water, controlled O. aegyptiaca by about 90% and 80% and increased crop yield 25–47% and 30%, respectively, without any crop injury symptoms. Repeated applications of the same herbicides at half rates resulted in slightly higher O. aegyptiaca control and crop yield than only one herbicide application at double rate. Chemigation by the sprinkler systems (microsprinklers, 60 m3 ha−1) slightly increased the herbicide efficiency as compared with the high volume spray (800 m3 ha−1). O. aegyptiaca control from sulfonylureas applied by drip chemigation was poor, as this probably requires very accurate timing and the herbicide distribution in the soil was not uniform.
A stochastic simulation model for evaluating the concept of patch spraying
Authors: PAICE  , DAY  , REW  , HOWARD
Published: March 2003

The long‐term economic benefits of `patch' spraying are likely to be related to the initial spatial distribution of the target weeds, the demographic characteristics of the species and the weed control and crop husbandry practices to which they are subjected. This paper describes a stochastic simulation model developed to investigate the interaction between weed seed dispersal and patch spraying. Simulated weed plant and seed populations are generated and compared with data from field observations. Lloyd's Patchiness index is used to quantify the patchiness of the weed density distribution, and the parameter k of the negative binomial distribution is used as a measure of distribution shape. A method of assessing the spatial scale of weed aggregation is proposed, in which spatial weed density information is transformed into the frequency domain, using a discrete two‐dimensional Fourier transform. In this paper, we simulate `on/off' patch spraying (full or zero herbicide application rate). A quantitative analysis of the effects of sprayer resolution and weed seed dispersal range on the herbicide reduction and yield benefits from patch spraying is performed for three initial spatial seedbank distributions. The model is parameterized for the grass weed Alopecurus myosuroides Huds. Herbicide is applied in square areas (whose size is defined by the spatial resolution of the sprayer) in which mean weed density is greater than or equal to one plant m–2. For a system conforming to this specification we show that for the control of A. myosuroides, it is unlikely that patch spraying would be profitable in the long term if the control area is larger than 6 m × 6 m. In some circumstances higher resolution may be required.
Effect of fungal toxins on germination of Striga hermonthica seeds
Authors: ZONNO  , VURRO
Published: March 2003

Fourteen fungal toxins were assayed in vitro to evaluate their effect on seed germination of the parasitic weed Striga hermonthica. Among them, T‐2 toxin proved to be the most active, being able to inhibit 100% seed germination at 10−5 M, and being still active when tested at a concentration of 10−7 M (19% inhibition). Deoxinivalenol was also very active, causing 100% and 69% reduction in germination when assayed at 10−4 and 10−5 M respectively. Cytochalasin E, tenuazonic acid, fumonisin B1, enniatin and nivalenol were shown to have an inhibitory effect of around 50% at 10−4 M, whereas other toxins had lower or no activity. The high activity shown by some fungal toxins suggests that they may have potential for use as more natural and safe herbicides to suppress parasite seed germination.
The role of ecology in the development of weed management systems: an outlook
Authors: Mortensen  , Bastiaans  , Sattin
Published: March 2003

This paper discusses the extent to which a knowledge of weed biology and ecology can contribute to the development of weed management strategies. To date, such contributions have been modest and have been constrained by a number of factors that are discussed in this review. In contrast to other pest management disciplines, devising integrated weed management strategies that address a diversity of weed species with a diversity of life history traits is difficult. Because of this diversity, robust systems that require ecological insight beyond that of individual species are needed. Although the contributions have been modest, research findings have helped to shape weed management strategies in a number of important ways. Approaches directed at weed population management have revealed important insights into population equilibria, density‐dependent mortality and life stages particularly important in regulating population size. Eco‐physiological research has helped to guide the development of biologically effective herbicide dosage strategies, whereas mechanistic interplant competition modelling coupled with empirical field studies have aided in the identification of weed‐suppressive crop phenotypes. Finally, much has been learned about the influence of control tactics and agronomic measures on the evolution of herbicide resistance and the development of integrated weed management strategies to address it. In this paper, examples are reviewed where research in ecology and biology has helped to shape the practice of integrated weed management. More importantly, characteristics of such research programmes are identified so that future efforts in the discipline will have a context in which the relevance of research questions and approaches can be considered.
Increased efficacy of clodinafop‐propargyl by terpineols and synergistic action with esterified fatty acids
Authors: Cabanne
Published: March 2003

A novel chemistry, namely terpene alcohols from pine tree (Pinus pinaster Ait.) was assessed as adjuvants for herbicides. The compared adjuvants included butylated fatty acids from tall oil, a blend of terpene alcohols, mainly isomers of terpineols, from pine oil and three mixtures containing butylated fatty acids and terpineols. All were emulsified with the same non‐ionic vegetable surfactant present at 25% (wt/wt). Whole‐plant bioassays were performed in the greenhouse with Alopecurus myosuroides Huds. and oats to compare the effects of these vegetable‐based adjuvants on the efficacy of clodinafop‐propargyl. Formulated clodinafop‐propargyl, with its safener and adjuvants added in tank‐mixture, was applied at the 2‐leaf stage of the plants. The effects of adjuvants were compared on the basis of doses of herbicide producing the same effect. Herbicide efficacy was increased less than twofold by the emulsifier, 2–3‐fold by butylated seed oil and 5–6‐fold by terpineols. The optimum effect of terpineols was observed at 0.5% (V/V). The addition of terpineols to butylated fatty acids (mixture ratio 0.5:0.5; wt/wt) increased the effect of esterified fatty acids up to the level of terpineols. A synergistic joint action was demonstrated when analysed with the Additive Dose Model. The interest of terpineols as adjuvants of herbicides is discussed.
Inheritance of tolerance to metribuzin in durum wheat
Authors: Villarroya  , Escorial  , Garcia‐Baudin  , Chueca
Published: March 2003

The inheritance of tolerance to the herbicide metribuzin was studied in two durum wheat cultivars, one of which, ‘Anton’, is resistant and one, ‘Nita’, susceptible. Parents, F1, F2 and F3 of the crosses ‘Anton’ × ‘Nita’ and ‘Nita’ × ‘Anton’ were tested for herbicide response. The character evaluated was the increase in weight of plants treated with the herbicide. As there were no significant differences between progenies of reciprocal crosses, cytoplasm was not involved in tolerance. Tolerance was semi‐dominant with means values of F1, F2 and F3 progenies in the range of mid‐parent. The heritability of this trait estimated by regression of the average of progeny F3 in their parent F2 had a value of 0.23 ± 0.063 and a value of 0.52 ± 0.150 estimated by the relation VG/VP for full‐sib F2 families.
Biochemical mechanisms of cross‐resistance to aryloxyphenoxypropionate and cyclohexanedione herbicides in populations of Avena spp.
Authors: Cocker  , Coleman  , Blair  , Clarke  , Moss
Published: March 2003

Aryloxyphenoxypropionate (APP) and cyclohexanedione (CHD) herbicides are used extensively in the UK to control grass weeds, including Avena spp. (wild‐oats). Reports of resistance to APP and CHD herbicides are a particular concern for the agricultural community. In this study, the responses of four UK Avena populations were characterized towards the APP herbicides fenoxaprop‐P‐ethyl and fluazifop‐P‐butyl, and towards the CHD herbicides cycloxydim and tralkoxydim. An A. sterilis ssp. ludoviciana population (T/41) was found to be highly resistant to fenoxaprop‐P‐ethyl and fluazifop‐P‐butyl, but did not show cross‐resistance to cycloxydim and tralkoxydim. In contrast, one A. sterilis ssp. ludoviciana (T/11) and one A. fatua population (Dorset) showed partial resistance to both APP herbicides and also showed cross‐resistance to the CHD herbicide tralkoxydim, but not to cycloxydim. Before this study, the biochemical mechanisms that confer resistance to the APP and CHD herbicides in UK Avena populations were unknown. Results from the present study show that an enhanced rate of metabolism of fenoxaprop‐P‐ethyl was found to confer resistance in the two partially resistant Avena populations (T/11 and Dorset), and the presence of an insensitive form of the target enzyme, ACCase, was responsible for target site resistance to fenoxaprop‐P‐ethyl and fluazifop‐P‐butyl in the highly resistant population T/41. Cross‐resistance to the CHD herbicide tralkoxydim in the T/11 and Dorset populations was not conferred by insensitive ACCase, and was most probably caused by enhanced metabolism. This is the first report that resistance to fenoxaprop‐P‐ethyl can be conferred by enhanced metabolism in Avena spp.
Ranking the ability of wheat varieties to compete with Lolium rigidum
Authors: Lemerle D , Verbeek B , Orchard B
Published: March 2003

The relative competitive advantage of 12 commercially available wheat varieties was examined against Lolium rigidum Gaud. at a number of sites from 1995 to 1997 in south‐eastern Australia. Nearly all the variation in crop grain yield was attributable to the variety × environment effects (81%), with only 4% due to variety × weed × environment effects. Some varieties exhibited an environment‐specific competitive advantage, for example Katunga, Dollarbird and Hartog, whereas others like Shrike, Rosella and Janz were relatively poorly competitive in some situations. The introduction of greater genetic variability into wheat is required to significantly increase competitiveness. Alternatively, manipulating crop agronomy, such as increasing crop seeding rate, may be a practical alternative. The grain yield of weed‐free wheat was highly positively correlated with grain yield of the weedy plots, suggesting that local adaptation is important for strong competitiveness, and that wheat breeders in southern Australia may be inadvertently selecting for competitive advantage with weeds when selecting for other traits such as early vigour. The varieties which showed competitive yield advantage also suppressed L. rigidum. A combination of short‐term agronomic manipulations and a longer‐term breeding effort is needed for increasing wheat competitiveness, and the increasing importance of herbicide‐resistant weeds may facilitate this process.
Quantitative aspects of Orobanche crenata infestation in faba beans as affected by abiotic factors and parasite soil seedbank
Authors: Manschadi A M , Sauerborn J , Stützel H
Published: March 2003

The interactions between the root parasitic weed Orobanche crenata Forsk. and its host plant faba bean (Vicia faba L.) were quantified under controlled and field conditions at ICARDA’s Tel Hadya research station. In the field experiments conducted in 1993–94 and 1994–95 faba beans were sown on two dates, in plots with 0, 50, 200 and 600 O. crenata seeds kg–1 soil, under both limited and sufficient moisture supply. The effects of temperature on the duration of the early developmental stages of O. crenata were investigated in a growth chamber. The extent of O. crenata infestation was closely related to the number of parasite seeds in the soil. The seed‐density treatment with 600 seeds kg–1 soil resulted in complete crop failure. Furthermore, O. crenata infestation was higher under sufficient than under limiting water supply conditions, irrespective of sowing date. Only in the moderately infested plots, did shifting of the planting time of faba bean result in a significant decrease in parasite dry weight and an increase in crop seed yield. The timing of germination, attachment and further developmental stages of O. crenata was not related to faba bean growth stage and was affected primarily by soil temperature. The duration of O. crenata developmental stages was estimated using the thermal time concept. The relationship between total number of parasite attachments at the harvest of the faba bean crop and O. crenata seed density was dependent on maximum faba bean root‐length density measured by the start of pod‐filling in each treatment combination of sowing date and moisture supply. The results are discussed with reference to implications for the development of a dynamic simulation model for the prediction of faba bean yield losses caused by O. crenata.
Can wild relatives of sorghum provide new sources of resistance or tolerance against Striga species?
Authors: Gurney A L , Press M C , Scholes J D
Published: March 2003

Summary The genus Striga contains some of the most noxious parasitic plants, which have a devastating impact on cereal production in Africa; of most importance are Striga hermonthica and Striga asiatica. Complete resistance to infection by Striga species does not exist in cultivated cereals. Of great interest is the possibility that wild relatives of cereals may provide a genetic basis for resistance or tolerance to infection and may be of enormous value for the development of resistant crops. A wild relative of cultivated sorghum, Sorghum arundinaceum, demonstrated tolerance to infection by S. asiatica, with little impact of S. asiatica on host growth or grain production compared with the detrimental impact of the parasite on cultivated sorghum. Infection by S.hermonthica, however, had a significant influence on host performance for both wild and cultivated sorghum. Differences in host:parasite responses may be explained by the timing of parasite attachment and differences in host specificity for these two Striga species.
An approach to the treatment of psychogenic parasitosis
Authors: Zanol Karen , Slaughter James , Hall Robert
Published: March 2003

BackgroundPatients with psychogenic parasitosis typically seek help from nonpsychiatric physicians and can be difficult and time‐consuming to treat. Pimozide has been promoted as the treatment of choice but is not indicated for every patient presenting with this symptom. Our purpose was to develop a realistic treatment protocol for the nonpsychiatric physician faced with these patients.

MethodsUsing what is known about this problem through review of the literature and our own experience with 20 patients, a practical treatment strategy is suggested.

ResultsIt is proposed that dermatologists and primary care professionals seeing these patients determine (1) whether or not the patient's belief in infestation is shakable and (2) whether or not the patient is depressed, in order to chose a therapeutic plan.

ConclusionsDermatologists and psychiatrists can work together to develop treatment protocols that minimize risk and maximize therapy for patients with psychogenic parasitosis.
Superficial disseminate porokeratosis in a patient with myelodysplastic syndrome
Authors: Levin Robin M.. , Heymann Warren R..
Published: March 2003

NJ 08053[TAB]A 70‐year‐old man was admitted with a diagnosis of myelodysplastic syndrome (MDS) and fever of unknown origin. He had been diagnosed with MDS 2 months prior to admission, and was treated initially with the anabolic androgen, Danazol. He had also been on prednisone, 60 mg a day for a few months for the treatment of hemolytic anemia. Two weeks later, he noted the development of a mildly pruritic rash over his trunk and extremities. He denied any previous history of a similar rash as well as any family history of similar lesions. It was thought that he was having an allergic reaction to the Danazol and, therefore, Danazol was discontinued. The rash seemed to improve but flared again a few days prior to admission. Upon admission, his laboratory data revealed hemoglobin 9.3 gm/DL, hematocrit 27.3%, white blood cell count 3300/mm3 and platelet count 41,000/mm3. A bone marrow biopsy showed a hypercellular marrow. Chromosome analysis of the bone marrow revealed a complex karyotype including the loss of chromosomes 5 and 7, the presence of an isochromosome for the entire long arm of chromosome 17, and the presence of an additional chromosome 21; these are characteristic chromosome aberrations in myelodysplastic syndromes. Physical examination demonstrated discrete, small, thread‐like, annular papules over the trunk and extremities (
Fig. 1). A skin biopsy was performed and was compatible with porokeratosis showing a typical cornoid lamella (
Fig. 2). He was not given any treatment for his skin lesions and treatment for his MDS consisted solely of red cell concentrates.

Multiple annular papules with a thread‐like border as seen in porokeratosis

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A typical cornoid lamella characteristic of porokeratosis

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Angina bullosa hemorrhagica
Authors: Grinspan David , Abulafia Jorge , Lanfranchi Héctor , DDS .
Published: March 2003

Background In 1967, Badham used the term angina bullosa hemorrhagica (ABH) to describe an entity we already knew as traumatic oral hemophlyctenosis (TOH) (1933) and later renamed recurrent oral hemophlyctenosis (ROH) (1971).

Objectives The objective of this study was to review and discuss the literature, and to report 54 new cases seen between 1989 and 1996.

Materials and methods Fifty‐four patients were thoroughly assessed to determine the clinical features, histology, etiology, pathogenesis, differential diagnosis, and therapy.

Results In 35 patients (64.8%), the lesions predominated on the palate and in nine (16.6%) on the oral mucosa. The incidence was similar in both sexes (women, 52%; men, 48%) and the condition affected mostly the 51–70‐year age group. ABH was never documented in children under 10 years of age. In 24 cases (44.4%), diabetes mellitus, hyperglycemia, and/or a family history of diabetes was found.

Conclusions ABH is a disorder more common than the literature would suggest. Although the causes may be multiple (mucosal trauma, inhaled corticosteroids), the available data indicate that, in these patients, the presence of an alteration in glucose metabolism should be considered.
Childhood, neonatal, and stillborn pemphigus vulgaris
Authors: Bjarnason Bolli , Flosadóttir Ellen , Dds .
Published: March 2003

Background Childhood, neonatal, and stillborn cases of pemphigus vulgaris were reviewed.

Methods From an examination of the pemphigus vulgaris literature, 46 childhood cases, nine neonatal cases, and three stillborn cases were found and investigated.

Results In the childhood cases, the ratio between the sexes is approximately the same. The mean age of onset is 12 years, with only 11 children being 10 years of age or younger. Some children were treated with adjuvants to corticosteroids, most of them with azathioprine. While only one childhood case has been reported as fatal, the long‐term prognosis and the relationship of early treatment and outcome are unknown. Neonatal prognosis, however, is excellent. Both neonatal and stillborn cases are probably the result of transplacental transmission of maternal antibodies. The connection between maternal antibody titer and fetal mortality is unknown. All stillborn cases reviewed died during the eight month of gestation. Immunosuppressive treatment probably affects fetal survival. In women with an active disease, who have had the disease, or who are monozygotic siblings to such patients, the possibility of the fetus developing the disease must be considered.

Conclusions It is essential that physicians be aware of the existence of childhood pemphigus vulgaris in order to make an early diagnosis and to avoid treatment delay. More childhood case reports are needed to obtain better information on optimal treatment, and authors should be encouraged to report the follow‐up of their cases.
Plaque‐type blue nevus combined with nevus spilus and smooth muscle hyperplasia
Authors: Park Young Min , Kang Hoon , Cho Baik Kee
Published: March 2003

A 31‐year‐old man presented with a large pigmented lesion, present since birth on his right upper aspect of his back. On examination, a speckled pigmented plaque measuring 9 × 5 cm was found on the right interscapular area. The plaque was composed of multiple dark‐blue macules and papules with intervening areas of faint blue discoloration and brown patches overlapping the blue lesions ( Fig. 1). The lesion was slightly elevated, showing a gradual increase in height from its periphery toward its center. The lesion had enlarged as the patient grew, but there had been no change in color, size, or texture over the past few years. No other pigmentary changes were noted, and there was no family history of pigmentary disorders.

A large speckled plaque composed of an aggregation of many deep blue macules, papules and small brown patches with intervening areas of faint blue discoloration

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Three skin biopsy specimens were obtained. In the dark‐blue papular and macular area, many melanin‐laden cells were present in the mid to lower portion of the dermis; these aggregated around blood vessels, the cutaneous nerve, and the pilosebaceous apparatus, and were intimately mixed with irregularly arranged, slightly thickened collagen bundles ( Fig. 2). Many were spindle‐shaped, bipolar, dendritic melanocytes, some extending into the subcutaneous tissue. A few melanophages were intermingled with the melanocytes. Some sections contained proliferations of thickened arrector pili muscles. In the brown patches overlapped by the faint blue background area, rete ridges were elongated and the levels of melanin and melanocytes in the epidermal basal layer were slightly increased. Numerous melanocytes were scattered in the mid to lower dermis. These features were consistent with a common blue nevus accompanied by nevus spilus and smooth muscle hyperplasia.

(A) Clumps of melanocytes intermingled with irregularly arranged collagen bundles in the mid and lower dermis. (B) Smooth muscle hyperplasia around pilar structures in the lower part of the dermis. Hematoxylin and eosin. Original magnification: A, ×40; B, ×400

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Immunohistochemical studies demonstrated a positive reaction of the tumor cells to vimentin and S‐100 protein. In addition, many cells reacted to the antibody HMB‐45, indicating the presence of premelanosomes. The patient did not wish to undergo surgical treatment, and it was recommended that the condition be monitored regularly to detect promptly any malignant changes.
T‐cell chronic lymphocytic leukemia mimicking dermatomyositis
Authors: Nousari Hossein C. , Kimyai‐Asadi Arash , Huang Chia‐Hui V. , Tausk Francisco A.
Published: March 2003

A 57‐year‐old man was diagnosed with chronic lymphocytic leukemia (CLL) during routine hematologic evaluation. Two months later, the patient developed a mildly pruritic periorbital eruption and erythematous plaques in a photosensitive distribution. A skin biopsy at an outside institution showed nonspecific histopathologic changes. The patient was diagnosed with amyopathic dermatomyositis and treated with prednisone 1 mg/kg/day with no improvement. The patient was subsequently admitted to our institution for CLL chemotherapy.

Physical examination on admission revealed bilateral, violaceous, nonblanching periorbital plaques (Fig. 1A)and symmetric erythematous plaques with mottled hypo‐ and hyperpigmentation on the shoulders, proximal arms (Fig. 1B), and upper chest (Fig. 1C). Periungual erythema was noted. Muscle strength was normal. Laboratory examination was significant for a white cell count of 33,700/mm3 with 78% lymphocytes, a hematocrit of 25.8%, and a platelet count of 25,000/mm3. The lymphocytes were almost exclusively CD4 T cells expressing CD2, CD3, CD5, and CD7. Electrolytes, liver function tests, creatine kinase, aldolase, antinuclear antibodies, and anti‐Jo antibodies were normal or negative. Several biopsies of the plaques on the arms were obtained. Histopathology revealed leukemic infiltration of the skin with monoclonal T lymphocytes positive for CD2, CD3, CD4, CD5, and CD7 (
Fig. 2). Steroids were discontinued. The patient died a week later from toxic epidermal necrolysis secondary to allopurinol.

Clinical findings included periorbital violaceous plaques mimicking a heliotrope eruption (a) and poikilodermatous‐appearing plaques on the lateral arms (b) and upper chest (c)

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Histopathology of a biopsy from the arm revealing dense dermal leukemic infiltrates with periadnexal accentuation

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Search for evidence of a Th2 profile in HIV+ patients
Authors: Galhardo Maria Clara Gutierrez , Perez Maurício , Morgado Mariza Gonçalves , Almeida Sônia , De Azevedo Lúcia Maria Soares , Georg Ingerborg , Ferreira Helen , Sarno Euzenir Nunes
Published: March 2003

Background Hypersensitivity dermatoses are common in human immunodeficiency virus‐positive (HIV+) patients, particularly as the disease progresses. Studies have shown that a switch to T‐helper 2 (Th2) might represent a turning point in HIV. This study investigated whether increases in the number of skin mast cells, immunoglobulin E (IgE) serum levels, and eosinophilia, involved in the Th2 response in allergic disease, might also be present in HIV+ patients. If so, these alterations might explain one of the mechanisms of skin hypersensitivity in these patients.

Methods Forty‐five skin biopsies from the normal skin of the upper arm of HIV+ patients and 15 controls were included in the study. HIV+ individuals were classified into three equal categories according to their immunologic status: Category I (< 200/μL), Category II (200–499/μL), and Category III (> 500/μL). Anti‐tryptase antibody was employed in tissue sections to show mast cells; IgE serum levels and eosinophils in peripheral blood count were investigated; delayed‐type hypersensitivity (DTH) skin tests (candidin, trichophytin, and PPD 2U) were evaluated.

Results Normal cutaneous mast cell and eosinophil counts were the same in all categories and in the control group, but increased IgE levels (P < 0.01) and DTH skin test anergy (P < 0.006) were observed among acquired immunodeficiency syndrome (AIDS) patients.

Conclusions The density of skin mast cells in HIV infection was not modified in the course of the disease. Mast cells do not seem to be primarily responsible for triggering hypersensitivity dermatoses among AIDS patients, although data in support of the Th2 response, as seen in increased IgE serum levels and DTH anergy, are present.
Mast cells in leprosy and leprosy reaction
Authors: Mahaisavariya Punkae , Jiamton Sukhum , Manonukul Jane , Khemngern Supakan
Published: March 2003

Background Mast cells can be visualized in routine, acid‐fast‐staining, paraffin tissue section as metachromatic staining cells, and can be activated to release inflammatory mediators which play a role in the cell‐mediated immune response.

Methods Skin biopsy tissues were taken from the most active skin lesion of each leprosy patient at the time of diagnosis (nonreactional group) and at the time of reaction (reactional group) during the years 1994–1997 in the leprosy clinic at the Department of Dermatology, Faculty of Medicine, Siriraj Hospital, Mahidol University, Thailand. Mast cells were identified by metachromatic staining (purple) in Fite's stain sections and reported as the average number of cells per high power field in three compartments: at the center and periphery of the granuloma and in the interstitium. The data were analyzed in three groups: nonreactional group, type I, and type II leprosy reactions. The mast cell count of each group and each compartment of the section, expressed as the mean ± standard error, was compared.

Results A total of 95 persons were included in the study, but 108 tissue sections were obtained due to nine cases having more than one section. Of these patients, 63 cases (66.32%) had no reaction, 19 cases (20%) had type I reaction, and 13 cases had type II reaction. There was no difference in age and sex among these groups. The mast cell count in the interstitium was higher than that within the granuloma, both at the center and at the periphery, in every type, and the count in this area reduced significantly in leprosy reactions, both type I and type II, compared with the nonreactional group.

Conclusions The change in the average mast cell number in nonreactional leprosy and leprosy reactions may indicate the important role of mast cells in dynamic changes in the cell‐mediated immune response in leprosy and leprosy reactions.