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Early Infection (early + infection)
Selected AbstractsEarly infection of Fagus sylvatica by Heterobasidion annosum sensu strictoFOREST PATHOLOGY, Issue 5 2008Akomy Summary Heterobasidion annosum sensu stricto is the most important damaging agent in Scots pine stands planted on the former agricultural lands in Poland. The routine action in pine stands which have lost stability because of H. annosum root rot is to change stand management, including species conversion. In many cases, the Fagus sylvatica is used for this purpose. This study was the first assessment of widespread infection by H. annosum in young F. sylvatica plantations. Disease symptoms included atrophy and yellowing of leaves, wilting and the presence of pathogen sporocarps around the root collars of young trees. Heterobasidion annosum s. s. was observed on both 4- and 17-year-old beech. Based on annual increments, the disease could be present for 3,4 years before tree death. A high incidence of H. annosum in pine stumps of previous stands (80,100%) and dry periods in recent years may be the main reasons for such common infection of F. sylvatica. This work also showed that mice and frost were not the main killing factors F. sylvatica in plantations. [source] Bean dwarf mosaic virus: a model system for the study of viral movementMOLECULAR PLANT PATHOLOGY, Issue 4 2010AVNER LEVY SUMMARY Taxonomy:Bean dwarf mosaic virus -[Colombia:1987] (BDMV-[CO:87]) is a single-stranded plant DNA virus, a member of the genus Begomovirus of the family Geminiviridae. Physical properties: BDMV virions are twinned incomplete isosahedra measuring 18 × 30 nm. The viral particle is composed of 110 subunits of coat protein, organized as 22 pentameric capsomers. Each subunit has a molecular mass of ,29 kDa. BDMV possesses two DNA components (designated DNA-A and DNA-B), each ,2.6 kb in size. Host range: The natural and most important host of BDMV is the common bean (Phaseolus vulgaris). Nicotiana benthamiana is often used as an experimental host. Common bean germplasm can be divided into two major gene pools: Andean materials, which are mostly susceptible to BDMV, and Middle American materials, which are mostly resistant to BDMV. Disease symptoms: The symptom intensity in common bean plants depends on the stage of infection. Early infection of susceptible bean seedlings will result in severe stunting and dwarfing, leaf distortion and mottling or mosaic, as well as chlorotic or yellow spots or blotches. BDMV-infected plants usually abort their flowers or produce severely distorted pods. Late infection of susceptible plants or early infection of moderately resistant genotypes may show a mild mosaic, mottle and crumpling or an irregular distribution of variegated patches. Biological properties: As a member of the Begomovirus group, BDMV is transmitted from plant to plant by the whitefly Bemisia tabaci. BDMV is a nonphloem-limited virus and can replicate and move in the epidermal, cortical and phloem cells. As a nonphloem-limited virus, it is sap-transmissible. [source] Influence of maternal infection on offspring immune response in murine larval toxocariasisPARASITE IMMUNOLOGY, Issue 7 2003K. Reiterová SUMMARY The impact of Toxocara canis infection on the proportion of CD4+ and CD8+ T splenocytes, the serum concentrations of cytokine IFN-, and IL-5, and the production of Toxocara -specific antibodies were studied in two C57BL6/J mouse groups and their offspring. The mice were infected with 1000 T. canis eggs on the day of mating (early infection) and on day 14 of pregnancy (late infection). Early infection resulted in a significant increase of CD4+ T-cell subtype, however, a decline in CD8+ in comparison with late infection, as well as with non-infected control. The IFN-, serum concentrations decreased in infected mothers after the birth when compared with non-infected mothers, while in the offspring this cytokine was barely or not detectable. In the mothers of both infected groups, the humoral immune response included both parasite-specific IgM and IgG2 antibodies. While IgG1 levels remained constant throughout the whole experiment in mothers with early infection, late-infected mothers became seropositive only 3 weeks after delivery. IgM was not detectable in any offspring. Pups from early-infected mothers had IgG1 antibodies. Conversely, IgG2 was detectable in pups of both experimental infection groups. A significant difference was observed in the amounts of pups/litter of the infected mothers in comparison with the non-infected ones. Only 56% of females after early infection and 79% of those after late infection had a successful pregnancy. However, all mice of the control group produced a litter. The first T. canis larvae were detected in the muscles of the offspring of both groups on day 5 after the birth. These data show the changes in regulatory and cytotoxic immunity mechanisms of the infected mothers and their offspring and the high level of pregnancy loss as a result of larval toxocariasis. [source] Multicentre retrospective analysis of the outcome of artificial anal sphincter implantation for severe faecal incontinenceBRITISH JOURNAL OF SURGERY (NOW INCLUDES EUROPEAN JOURNAL OF SURGERY), Issue 11 2001Dr D. F. Altomare Background: A new prosthetic device, the ActiconTM artificial anal sphincter, has recently been introduced for treating severe faecal incontinence. The results of this procedure in 28 patients are presented. Methods: The patients underwent operation for severe faecal incontinence in four Italian university hospitals and patients were reviewed after a median follow-up of 19 (range 7,41) months. Results: Early infections occurred in four patients, requiring removal of the device in three. Dehiscence of the perineal wound occurred in nine patients. After activation of the device, the cuff had to be removed in a further four patients (for rectal erosion in two, anal pain in one and late infection in one). The cuff was accidentally broken in one patient. A new anal cuff was repositioned successfully in two patients. Overall, five patients had complete removal of the device and two removal of the cuff only. Twenty-one patients available for long-term evaluation had a major improvement in faecal continence. Median resting anal pressure increased from 27 mmHg before surgery to 32 mmHg after operation. Preoperative squeeze pressure was 42 mmHg while maximum postoperative anal pressure with the activated device was 67 mmHg. The median American Medical System incontinence score decreased significantly from 98·5 to 5·5 (P < 0·001). Similar figures were observed using the Continence Grading Scale (from 14·9 to 2·6; P < 0·001). Twelve patients developed symptoms of obstructed defaecation while two patients complained of anal pain. Conclusion: Improved continence was achieved after neosphincter implantation in three-quarters of the patients. Early infection and rectal erosion, together with difficulty in evacuating, are still major concerns with this technique. © 2001 British Journal of Surgery Society Ltd [source] Induced Resistance by , -Aminobutyric Acid in Artichoke against White Mould Caused by Sclerotinia sclerotiorumJOURNAL OF PHYTOPATHOLOGY, Issue 10 2010Emanuela Marcucci Abstract ,-aminobutyric acid (BABA) was assessed for the ability to protect two artichoke cultivars, C3 and Exploter, against white mould caused by Sclerotinia sclerotiorum, which represents a major problem in the cultivation of this crop in many growing areas of Central Italy. Changes in the activity and isoenzymatic profiles of the pathogenesis-related (PR) proteins ,-1,3-glucanase, chitinase and peroxidase in plantlets upon BABA treatment and following inoculation of the pathogen in plantlets and leaves detached from adult plants were also investigated as molecular markers of induced resistance and priming. BABA treatments by soil drenching induced a high level of resistance against S. sclerotiorum in artichoke plantlets of both cultivars C3 and Exploter with a similar level of protection and determined a consistent increase in peroxidase activity paralleled with the differential induction of alkaline isoenzyme with a pI 8.6. A consistent change was found in Exploter in the peroxidase activity following BABA treatments and pathogen inoculation and was paralleled with the expression of an anionic band in plantlets and both anionic and cationic bands in leaves. Our results showed a correlation between BABA-induced resistance (BABA-IR) and a augmented capacity to express basal defence responses, more pronounced in cultivar C3 and associated ,-1,3-glucanase accumulation in both plantlets and leaves inoculated with the pathogen, whereas chitinase resulted affected only at plantlet stage. The present results represent the first one showing the effect of BABA in inducing resistance in artichoke and associated accumulation of selected PRs. If confirmed in field tests, the use of BABA at early plant stages may represent a promising approach to the control soilborne pathogens, such as the early infection of S. sclerotiorum. [source] Bean dwarf mosaic virus: a model system for the study of viral movementMOLECULAR PLANT PATHOLOGY, Issue 4 2010AVNER LEVY SUMMARY Taxonomy:Bean dwarf mosaic virus -[Colombia:1987] (BDMV-[CO:87]) is a single-stranded plant DNA virus, a member of the genus Begomovirus of the family Geminiviridae. Physical properties: BDMV virions are twinned incomplete isosahedra measuring 18 × 30 nm. The viral particle is composed of 110 subunits of coat protein, organized as 22 pentameric capsomers. Each subunit has a molecular mass of ,29 kDa. BDMV possesses two DNA components (designated DNA-A and DNA-B), each ,2.6 kb in size. Host range: The natural and most important host of BDMV is the common bean (Phaseolus vulgaris). Nicotiana benthamiana is often used as an experimental host. Common bean germplasm can be divided into two major gene pools: Andean materials, which are mostly susceptible to BDMV, and Middle American materials, which are mostly resistant to BDMV. Disease symptoms: The symptom intensity in common bean plants depends on the stage of infection. Early infection of susceptible bean seedlings will result in severe stunting and dwarfing, leaf distortion and mottling or mosaic, as well as chlorotic or yellow spots or blotches. BDMV-infected plants usually abort their flowers or produce severely distorted pods. Late infection of susceptible plants or early infection of moderately resistant genotypes may show a mild mosaic, mottle and crumpling or an irregular distribution of variegated patches. Biological properties: As a member of the Begomovirus group, BDMV is transmitted from plant to plant by the whitefly Bemisia tabaci. BDMV is a nonphloem-limited virus and can replicate and move in the epidermal, cortical and phloem cells. As a nonphloem-limited virus, it is sap-transmissible. [source] Influence of maternal infection on offspring immune response in murine larval toxocariasisPARASITE IMMUNOLOGY, Issue 7 2003K. Reiterová SUMMARY The impact of Toxocara canis infection on the proportion of CD4+ and CD8+ T splenocytes, the serum concentrations of cytokine IFN-, and IL-5, and the production of Toxocara -specific antibodies were studied in two C57BL6/J mouse groups and their offspring. The mice were infected with 1000 T. canis eggs on the day of mating (early infection) and on day 14 of pregnancy (late infection). Early infection resulted in a significant increase of CD4+ T-cell subtype, however, a decline in CD8+ in comparison with late infection, as well as with non-infected control. The IFN-, serum concentrations decreased in infected mothers after the birth when compared with non-infected mothers, while in the offspring this cytokine was barely or not detectable. In the mothers of both infected groups, the humoral immune response included both parasite-specific IgM and IgG2 antibodies. While IgG1 levels remained constant throughout the whole experiment in mothers with early infection, late-infected mothers became seropositive only 3 weeks after delivery. IgM was not detectable in any offspring. Pups from early-infected mothers had IgG1 antibodies. Conversely, IgG2 was detectable in pups of both experimental infection groups. A significant difference was observed in the amounts of pups/litter of the infected mothers in comparison with the non-infected ones. Only 56% of females after early infection and 79% of those after late infection had a successful pregnancy. However, all mice of the control group produced a litter. The first T. canis larvae were detected in the muscles of the offspring of both groups on day 5 after the birth. These data show the changes in regulatory and cytotoxic immunity mechanisms of the infected mothers and their offspring and the high level of pregnancy loss as a result of larval toxocariasis. [source] Viral load determines the B-cell response in the cerebrospinal fluid during human immunodeficiency virus infectionANNALS OF NEUROLOGY, Issue 5 2007Sabine Cepok PhD Objective Human immunodeficiency virus (HIV) infection of the central nervous system (CNS) is frequently associated with intrathecal immunoglobulin synthesis and cerebrospinal fluid (CSF) pleocytosis, but little is known about the B-cell response in the CSF of these patients. In this study, we investigated the relation between virus load and the frequency and phenotype of B cells in the CSF of HIV-infected patients. Methods The distribution of T cells, B cells, short-lived plasmablasts, and long-lived plasma cells was analyzed by flow cytometry in CSF and peripheral blood of 33 patients with HIV infection compared with 12 patients with noninfectious CNS diseases. HIV RNA copy number in CSF and serum was quantified by kinetic polymerase chain reaction. Results B-cell and plasmablast levels were increased in the CSF of HIV-infected patients compared with patients with noninfectious CNS diseases. Whereas CSF B cells were found at similar frequency during early and late stages of HIV infection, plasmablasts were more prevalent in the CSF during early infection. Plasmablasts in the CSF correlated with intrathecal IgG synthesis and even stronger with HIV RNA copy numbers in CSF, in particular, in untreated, early HIV-infected individuals. Initiation of antiviral treatment in therapy-naive patients strongly decreased HIV copy numbers and plasmablasts in CSF. Interpretation Our findings demonstrate that HIV infection of the CNS triggers an early profound B-cell response, with plasmablasts serving as the main virus-related B-cell subset in the CSF. Ann Neurol 2007 [source] Anaplasma phagocytophilum AnkA is tyrosine-phosphorylated at EPIYA motifs and recruits SHP-1 during early infectionCELLULAR MICROBIOLOGY, Issue 5 2007Jacob W. IJdo Summary Anaplasma phagocytophilum is an intracellular pathogen that infects and survives in neutrophilic granulocytes. The A. phagocytophilum genome encodes a type four secretion system (T4SS) that may facilitate intracellular survival by translocation of virulence factors, but to date, no such factors have been identified. Because T4SS-translocated proteins of several intracellular organisms undergo tyrosine phosphorylation by host cell kinases, we investigated tyrosine phosphorylation of A. phagocytophilum proteins during infection. Within minutes after incubation of A. phagocytophilum with HL-60 cells or PMN, a 190 kDa bacterial protein, AnkA, was increasingly tyrosine-phosphorylated. A. phagocytophilum binding to host cells without entry was sufficient for AnkA tyrosine phosphorylation. An in vitro Src kinase assay demonstrated that purified AnkA expressed in Escherichia coli was phosphorylated at tyrosines located at the C-terminal portion of AnkA. Similarly, AnkA expressed in COS-7 cells underwent tyrosine phosphorylation by Src at the C-terminus. The phosphorylated tyrosines were located in EPIYA motifs that display the consensus sequence for binding to SH2 domains. Immunoprecipitation studies demonstrated AnkA binding to the host cell phosphatase SHP-1 during early infection. Phosphorylation of the EPIYA motifs and the presence of the SH2 domains were necessary for AnkA,SHP-1 interaction. We conclude that AnkA is a translocated virulence factor that is tyrosine-phosphorylated by host cell kinases upon translocation into the host cell early during infection. A. phagocytophilum may manipulate the host cell through SHP-1 recruitment. [source] Survival of infants in the context of prevention of mother to child HIV transmission in South AfricaACTA PAEDIATRICA, Issue 5 2010M Chopra Abstract Aim:, We sought to study the survival of newborn children according to HIV status of the mother, that of the child and the timing of infection. Methods:, This is a prospective cohort study of 883 mothers (665 HIV-positive and 218 HIV-negative) and their infants. Data were collected using semi-structured questionnaires during home visits between the antenatal period and 36 weeks post-delivery. Infant HIV status was determined at 3, 24 and 36 weeks by HIV DNA PCR. Results:, The majority (81.3%) of infected infants who died were infected by 3 weeks of age. Of the HIV-exposed infants who died, 19 (28.4%) died before 6 weeks and 38 (56.7%) died by 12 weeks. The hazard ratio (HR) of mortality at 36 weeks of age in HIV-infected infants compared with exposed but negative infants was 8.9 (95% CI: 6.7,11.8). There was no significant difference in 36 week survival rates between HIV-non-exposed and HIV-exposed but negative infants (HR: 0.7; 95% CI: 0.3,1.5). The infant being HIV-positive at age 3 weeks (HR: 32 95% CI: 14.0,73.1) and rural site (HR: 4.4 95% CI: 1.2,23.4) were the two independent risk factors for infant death amongst HIV-exposed infants. Conclusion:, The prognosis for infants with early HIV infection was very poor in this cohort. A greater focus on prevention of early infection, earlier screening for HIV infection and access to antiretrovirals for eligible infants is recommended. [source] | |||||||||||||