The Experts below are selected from a list of 1353 Experts worldwide ranked by ideXlab platform
Michelle Heck - One of the best experts on this subject based on the ideXlab platform.
-
diaphorina citri nymphs are resistant to morphological changes induced by candidatus liberibacter asiaticus in midgut epithelial cells
Infection and Immunity, 2018Co-Authors: Marina Mann, Somayeh Fattahhosseini, Eldesouky Ammar, Richard R Stange, Ericarose Warrick, Kasie Sturgeon, Robert G Shatters, Michelle HeckAbstract:"Candidatus Liberibacter asiaticus" is the causative bacterium associated with citrus greening disease. "Ca Liberibacter asiaticus" is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri insects reared on healthy or "Ca Liberibacter asiaticus"-infected citrus trees using quantitative PCR, confocal microscopy, and mitochondrial superoxide staining for evidence of oxidative stress. Consistent with its classification as propagative, "Ca Liberibacter asiaticus" titers were higher in adults than in nymphs. Our previous work showed that adult D. citri insects have basal levels of Karyorrhexis (fragmentation of the nucleus) in midgut epithelial cells, which is increased in severity and frequency in response to "Ca Liberibacter asiaticus." Here, we show that nymphs exhibit lower levels of early-stage Karyorrhexis than adults and are refractory to the induction of advanced Karyorrhexis by "Ca Liberibacter asiaticus" in the midgut epithelium. MitoSox Red staining showed that guts of infected adults, particularly males, experienced oxidative stress in response to "Ca Liberibacter asiaticus." A positive correlation between the titers of "Ca Liberibacter asiaticus" and the Wolbachia endosymbiont was observed in adult and nymph midguts, suggesting an interplay between these bacteria during development. We hypothesize that the resistance of the nymph midgut to late-stage Karyorrhexis through as yet unknown molecular mechanisms benefits "Ca Liberibacter asiaticus" for efficient invasion of midgut epithelial cells, which may be a factor explaining the developmental dependency of "Ca Liberibacter asiaticus" acquisition by the vector.
Michelle Cilia - One of the best experts on this subject based on the ideXlab platform.
-
morphological abnormalities and cell death in the asian citrus psyllid diaphorina citri midgut associated with candidatus liberibacter asiaticus
Scientific Reports, 2016Co-Authors: Murad Ghanim, Somayeh Fattahhosseini, Amit Levy, Michelle CiliaAbstract:Candidatus Liberibacter asiaticus (CLas) is a phloem-limited, gram-negative, fastidious bacterium that is associated with the development of citrus greening disease, also known as Huanglongbing (HLB). CLas is transmitted by the Asian citrus psyllid (ACP) Diaphorina citri, in a circulative manner. Two major barriers to transmission within the insect are the midgut and the salivary glands. We performed a thorough microscopic analysis within the insect midgut following exposure to CLas-infected citrus trees. We observed changes in nuclear architecture, including pyknosis and Karyorrhexis as well as changes to the actin cytoskeleton in CLas-exposed midgut cells. Further analyses showed that the changes are likely due to the activation of programmed cell death as assessed by Annexin V staining and DNA fragmentation assays. These results suggest that exposure to CLas-infected trees induces apoptotic responses in the psyllid midgut that should be further investigated. Understanding the adaptive significance of the apoptotic response has the potential to create new approaches for controlling HLB.
Paul S Thorner - One of the best experts on this subject based on the ideXlab platform.
-
mib 1 index as a surrogate for mitosis Karyorrhexis index in neuroblastoma
The American Journal of Surgical Pathology, 2015Co-Authors: Taywin Atikankul, Yupapin Atikankul, Paula Marrano, Shanop Shuangshoti, Sakun Santisukwongchote, Paul S ThornerAbstract:Neuroblastoma, the most common extracranial solid tumor in infancy, shows marked biological heterogeneity. Multiple prognostic markers are combined to risk-stratify neuroblastoma patients for treatment. One marker assesses histology, dividing patients into favorable and unfavorable categories based, in part, on the mitosis-Karyorrhexis index (MKI). The recommended scoring of 5000 cells is, however, time-consuming and observer-dependent, and accurate counts may not always be performed. In the present study, we investigated using MIB-1 as a surrogate marker for the MKI. Twenty-five cases of neuroblastoma, ranging from low to high MKI, were immunostained for MIB-1. A total of 375 microscopic fields were digitally captured with > 100,000 cells scored. The MIB-1 index was determined by image analysis and MKI, by manual counting of the same immunostained fields. There was a significant correlation between the MIB-1 index and MKI comparing all fields (r = 0.7869, P 20.87. For comparison, the calculations were repeated using a manual MIB-1 count on the same images. Similar significant correlations were obtained, with nearly identical cutoff values for MKI categories. This approach can facilitate determination of the MKI by assessing the MIB-1 index, either by image analysis or manual counting.
-
mib1 index as a surrogate for mitosis Karyorrhexis index in neuroblastoma
Pathology, 2014Co-Authors: Taywin Atikankul, Yupapin Atikankul, Paula Marrano, Shanop Shuangshoti, Paul S ThornerAbstract:Multiple prognostic markers are combined to risk-stratify neuroblastoma patients for treatment protocols. One such marker is a histologic assessment using the International Neuroblastoma Pathology Committee classification, which divides patients into favourable and unfavourable categories assessing, together with other parameters, the mitosis-Karyorrhexis index (MKI). The recommended counting of 5000 cells to assign MKI is, however, time-consuming and observer-dependent, and there is a potential for inaccuracy. In the present study, we investigated automating an assessment of the MKI using image analysis and MIB-1 (Ki-67) as a surrogate marker. Twenty five cases of neuroblastoma, ranging from low to high MKI, were immunostained for MIB-1. A total of 375 microscopic fields were captured with 109,763 cells scored. The MIB-1 index was determined by image analysis software whereas MKI was obtained by manual counting of the same immunostained fields. There was a significant correlation between the MIB-1 index and the MKI comparing all fields (r = 0.7869, p value
Martin Harris - One of the best experts on this subject based on the ideXlab platform.
-
histiocytic necrotizing lymphadenitis kikuchi fujimoto disease continuing diagnostic difficulties
Histopathology, 1998Co-Authors: Lia P Menasce, Saumitra S Banerjee, David Edmondson, Martin HarrisAbstract:Aims: To describe the clinicopathological and immunophenotypic features of 25 cases of Kikuchi–Fujimoto disease (K–F), which remains a poorly recognized entity and is still frequently confused with malignant lymphoma, and to discuss the main diagnostic problems experienced by the referring pathologist. Methods and results Haematoxylin and eosin sections of 27 lymph node biopsies were re-examined. Immunostains for B-lymphocytes, T-lymphocytes and macrophages were performed. Clinical and follow-up data were obtained through a questionnaire to the referring pathologist or from the patients' notes where available. The suggested initial diagnoses are discussed. The lymph nodes showed a necrotizing process characterized by patchy or confluent areas of necrosis associated with Karyorrhexis and absence or paucity of granulocytes. This was associated with a proliferation of large blastic cells consisting of a mixture of T-lymphocytes and histiocytes. Fragmentation of the biopsy was a frequent feature. The diagnosis of K–F was suggested by the referring pathologist in three cases only. The most common suggested diagnosis was that of a non-Hodgkin's lymphoma. Conclusion This series documents continuing difficulties in the diagnosis of Kikuchi–Fujimoto disease in the UK and emphasizes that cases are still being mistakenly diagnosed as malignant lymphomas. The diagnosis of Kikuchi–Fujimoto disease merits active consideration in any nodal biopsy showing fragmentation, necrosis and Karyorrhexis, especially in young women presenting with cervical lymphadenopathy.
Somayeh Fattahhosseini - One of the best experts on this subject based on the ideXlab platform.
-
diaphorina citri nymphs are resistant to morphological changes induced by candidatus liberibacter asiaticus in midgut epithelial cells
Infection and Immunity, 2018Co-Authors: Marina Mann, Somayeh Fattahhosseini, Eldesouky Ammar, Richard R Stange, Ericarose Warrick, Kasie Sturgeon, Robert G Shatters, Michelle HeckAbstract:"Candidatus Liberibacter asiaticus" is the causative bacterium associated with citrus greening disease. "Ca Liberibacter asiaticus" is transmitted by Diaphorina citri more efficiently when it is acquired by nymphs rather than adults. Why this occurs is not known. We compared midguts of D. citri insects reared on healthy or "Ca Liberibacter asiaticus"-infected citrus trees using quantitative PCR, confocal microscopy, and mitochondrial superoxide staining for evidence of oxidative stress. Consistent with its classification as propagative, "Ca Liberibacter asiaticus" titers were higher in adults than in nymphs. Our previous work showed that adult D. citri insects have basal levels of Karyorrhexis (fragmentation of the nucleus) in midgut epithelial cells, which is increased in severity and frequency in response to "Ca Liberibacter asiaticus." Here, we show that nymphs exhibit lower levels of early-stage Karyorrhexis than adults and are refractory to the induction of advanced Karyorrhexis by "Ca Liberibacter asiaticus" in the midgut epithelium. MitoSox Red staining showed that guts of infected adults, particularly males, experienced oxidative stress in response to "Ca Liberibacter asiaticus." A positive correlation between the titers of "Ca Liberibacter asiaticus" and the Wolbachia endosymbiont was observed in adult and nymph midguts, suggesting an interplay between these bacteria during development. We hypothesize that the resistance of the nymph midgut to late-stage Karyorrhexis through as yet unknown molecular mechanisms benefits "Ca Liberibacter asiaticus" for efficient invasion of midgut epithelial cells, which may be a factor explaining the developmental dependency of "Ca Liberibacter asiaticus" acquisition by the vector.
-
morphological abnormalities and cell death in the asian citrus psyllid diaphorina citri midgut associated with candidatus liberibacter asiaticus
Scientific Reports, 2016Co-Authors: Murad Ghanim, Somayeh Fattahhosseini, Amit Levy, Michelle CiliaAbstract:Candidatus Liberibacter asiaticus (CLas) is a phloem-limited, gram-negative, fastidious bacterium that is associated with the development of citrus greening disease, also known as Huanglongbing (HLB). CLas is transmitted by the Asian citrus psyllid (ACP) Diaphorina citri, in a circulative manner. Two major barriers to transmission within the insect are the midgut and the salivary glands. We performed a thorough microscopic analysis within the insect midgut following exposure to CLas-infected citrus trees. We observed changes in nuclear architecture, including pyknosis and Karyorrhexis as well as changes to the actin cytoskeleton in CLas-exposed midgut cells. Further analyses showed that the changes are likely due to the activation of programmed cell death as assessed by Annexin V staining and DNA fragmentation assays. These results suggest that exposure to CLas-infected trees induces apoptotic responses in the psyllid midgut that should be further investigated. Understanding the adaptive significance of the apoptotic response has the potential to create new approaches for controlling HLB.