maria alejandra - Academia.edu (original) (raw)
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Panihati Mahavidyalaya, West Bengal State University
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Papers by maria alejandra
International Journal of Cancer, 1998
A crucial question in the study of tumor neuro-immunology concerns the capacity of the central ne... more A crucial question in the study of tumor neuro-immunology concerns the capacity of the central nervous system to initiate and execute an immune response. In a 100% fatal rat malignant glioma model, genetically modified tumors secreting INF-␥ intracerebrally generate an immune response resulting in a substantial increase in survival time, tumor rejection and specific systemic immunity. Tumors modified to secrete IL-2 alone do not change the biologic behavior of transfected gliomas. INF-␥ induces elevated expression of major-histocompatibility-complex-class-I and -class-II molecules in microglia throughout the brain and invokes enhanced tumor infiltration by CD4, CD8 and NK cells. These findings demonstrate successful immunization against a central-nervous-system tumor by direct priming in the brain with a live growth-competent tumor vaccine. Int.
Planta, 1968
Two phosphorylases could be detected on gel-electropherograms of leaf-extracts of Spinacia olerac... more Two phosphorylases could be detected on gel-electropherograms of leaf-extracts of Spinacia oleracea and of immature cotyledons of Vicia faba. These two phosphorylases could be separated by means of ammonium sulfate fractionation. Both the slower migrating phosphorylases from spinach and from beans, but not the fast one from beans, could be adsorbed on amyloplasts. This process takes place only when the amyloplasts are suspended in a salt medium. The slow phosphorylases can also be adsorbed on chloroplasts. The specific activity of the amyloplast-adsorbable phosphorylase in spinach leaves is about ten times higher in the cytoplasmatic fraction than in chloroplasts, a fact which suggests that this phosphorylase is localised in the cytoplasma. The addition of ADP or ATP to the reaction mixture had no influence on the synthesizing activity of the slow phosphorylases when they were tested with soluble amylopectin as a primer or while they were adsorbed on amyloplasts. The presence of ADPG and UDPG was inhibitory. The results reported above suggest that phosphorylase could catalyse the synthesis of starch in the plastids when photophosphorylation or oxidative phosphorylation occurs. This starch synthesis could be controlled by the concentration of ADPG. When, on the other hand, the ATP/Pi ratio is low, phosphorylase would be involved in starch breakdown. This reverse reaction is also regulated by the concentration of glucosylnucleotides. Durch Umfällung mit Ammoniumsulfat konnten die zwei, auf Gelelektropherogrammen nachweisbaren Phosphorylasen aus Blättern von Spinacia oleracea und aus unreifen Kotyledonen von Vicia faba getrennt werden. Die im elektrischen Feld langsamer wandernde Phosphorylase von Vicia und Spinat kann in Gegenwart salzhaltiger Medien auf Amyloplasten oder auch an Chloroplasten adsorbiert werden und dort den Aufbau von Stärke aus Glucose-1-Phosphat katalysieren. Das schneller wandernde Enzym aus Vicia faba zeigt diese Adsorption jedoch nicht. Die spezifische Aktivität der an Amyloplasten adsorbierbaren Phosphorylase aus Spinatblättern its in der cytoplasmatischen Fraktion etwa zehnfach höher als in den Chloroplasten. Die synthetisierende Aktivität der langsam wandernden Phosphorylasen wird durch ADP oder ATP nicht beeinflußt, dagegen hemmen sowohl ADP-Glucose als auch UDP-Glucose. Es wird die Möglichkeit diskutiert, daß Phosphorylase nicht nur den Abbau von Stärke katalysiert, sondern auch an ihrer Synthese in den Plastiden beteiligt ist, wenn Photophosphorylierung oder oxydative Phosphorylierung stattfindet.
International Journal of Cancer, 1998
A crucial question in the study of tumor neuro-immunology concerns the capacity of the central ne... more A crucial question in the study of tumor neuro-immunology concerns the capacity of the central nervous system to initiate and execute an immune response. In a 100% fatal rat malignant glioma model, genetically modified tumors secreting INF-␥ intracerebrally generate an immune response resulting in a substantial increase in survival time, tumor rejection and specific systemic immunity. Tumors modified to secrete IL-2 alone do not change the biologic behavior of transfected gliomas. INF-␥ induces elevated expression of major-histocompatibility-complex-class-I and -class-II molecules in microglia throughout the brain and invokes enhanced tumor infiltration by CD4, CD8 and NK cells. These findings demonstrate successful immunization against a central-nervous-system tumor by direct priming in the brain with a live growth-competent tumor vaccine. Int.
Planta, 1968
Two phosphorylases could be detected on gel-electropherograms of leaf-extracts of Spinacia olerac... more Two phosphorylases could be detected on gel-electropherograms of leaf-extracts of Spinacia oleracea and of immature cotyledons of Vicia faba. These two phosphorylases could be separated by means of ammonium sulfate fractionation. Both the slower migrating phosphorylases from spinach and from beans, but not the fast one from beans, could be adsorbed on amyloplasts. This process takes place only when the amyloplasts are suspended in a salt medium. The slow phosphorylases can also be adsorbed on chloroplasts. The specific activity of the amyloplast-adsorbable phosphorylase in spinach leaves is about ten times higher in the cytoplasmatic fraction than in chloroplasts, a fact which suggests that this phosphorylase is localised in the cytoplasma. The addition of ADP or ATP to the reaction mixture had no influence on the synthesizing activity of the slow phosphorylases when they were tested with soluble amylopectin as a primer or while they were adsorbed on amyloplasts. The presence of ADPG and UDPG was inhibitory. The results reported above suggest that phosphorylase could catalyse the synthesis of starch in the plastids when photophosphorylation or oxidative phosphorylation occurs. This starch synthesis could be controlled by the concentration of ADPG. When, on the other hand, the ATP/Pi ratio is low, phosphorylase would be involved in starch breakdown. This reverse reaction is also regulated by the concentration of glucosylnucleotides. Durch Umfällung mit Ammoniumsulfat konnten die zwei, auf Gelelektropherogrammen nachweisbaren Phosphorylasen aus Blättern von Spinacia oleracea und aus unreifen Kotyledonen von Vicia faba getrennt werden. Die im elektrischen Feld langsamer wandernde Phosphorylase von Vicia und Spinat kann in Gegenwart salzhaltiger Medien auf Amyloplasten oder auch an Chloroplasten adsorbiert werden und dort den Aufbau von Stärke aus Glucose-1-Phosphat katalysieren. Das schneller wandernde Enzym aus Vicia faba zeigt diese Adsorption jedoch nicht. Die spezifische Aktivität der an Amyloplasten adsorbierbaren Phosphorylase aus Spinatblättern its in der cytoplasmatischen Fraktion etwa zehnfach höher als in den Chloroplasten. Die synthetisierende Aktivität der langsam wandernden Phosphorylasen wird durch ADP oder ATP nicht beeinflußt, dagegen hemmen sowohl ADP-Glucose als auch UDP-Glucose. Es wird die Möglichkeit diskutiert, daß Phosphorylase nicht nur den Abbau von Stärke katalysiert, sondern auch an ihrer Synthese in den Plastiden beteiligt ist, wenn Photophosphorylierung oder oxydative Phosphorylierung stattfindet.