1,721,053 research outputs found
Immunolocalization of D-aminoacid oxidase in rat brain
No full textD-amino acid oxidase (D-AAO) is a peroxisomal flavoenzyme, the physiological substrate and the precise function of which are still unclear. We have investigated D-AAO distribution in rat brain, by immunocytochemistry, with an affinity-purified polyclonal antibody. Immunoreactivity occurred in both neuronal and glial cells, albeit at different densities. Glial immunostaning was strongest in the caudal brainstem and cerebellar cortex, particularly in astrocytes, Golgi-Bergmann glia, and tanycytes. Hindbrain neurons were generally more immunoreactive than those in the forebrain. Immunopositive forebrain cell populations included mitral cells in the olfactory bulb, cortical and hippocampal neurons, ventral pallidum, and septal, reticular thalamic, and paraventricular hypothalamic nuclei. Within the positive regions, not all the neuronal populations were equally immunoreactive; for example, in the thalamus, only the reticular and anterodorsal nuclei showed intense labelling. In the hindbrain, immunopositivity was virtually ubiquitous, and was especially strong in the reticular formation, pontine, ventral and dorsal cochlear, vestibular, cranial motor nuclei, deep cerebellar nuclei, and the cerebellar cortex, especially in Golgi and Purkinje cells
Autophagy of clofibrate-induced rat liver peroxisomes. Cytochemistry and immunocytochemistry.
No full textImmunocytochemical localization of D-amino acid oxidase in rat brain
No full textD-amino acid oxidase (D-AAO) is a peroxisomal flavoenzyme, the physiological substrate and the precise function of which are still unclear. We have investigated D-AAO distribution in rat brain, by immunocytochemistry, with an affinity-purified polyclonal
antibody. Immunoreactivity occurred in both neuronal and glial cells, albeit at different densities. Glial immunostaning was strongest in the caudal brainstem and cerebellar cortex, particularly in astrocytes, Golgi-Bergmann glia, and tanycytes.
Hindbrain neurons were generally more immunoreactive than those in the forebrain. Immunopositive forebrain cell populations included mitral cells in the olfactory bulb, cortical and hippocampal neurons, ventral pallidum, and septal, reticular thalamic, and paraventricular hypothalamic nuclei.Within the positive regions, not all the neuronal populations were equally immunoreactive; for example, in the thalamus, only the reticular and anterodorsal nuclei showed intense labelling. In the hindbrain, immunopositivity was virtually ubiquitous, and was especially strong in the reticular formation, pontine, ventral and dorsal cochlear, vestibular, cranial motor nuclei, deep cerebellar nuclei, and the cerebellar cortex, especially in Golgi and Purkinje cells
Immunohistochemical localization of peroxisomal enzymes during rat embryonic development
No full textPeroxisomes are cytoplasmic organelles involved in a variety of metabolic pathways. Thus far, the morphological and biochemical features of peroxisomes have been extensively characterized in adult tissues. However, the existence of congenital peroxisomal disorders, primarily affecting tissue differentiation, emphasizes the importance of these organelles in the early stages of organogenesis. We investigated the occurrence and tissue distribution of three peroxisomal enzymes in rat embryos at various developmental stages. By means of a highly sensitive biotinyl-tyramide protocol, catalase, acyl-CoA oxidase, and ketoacyl-CoA thiolase were detected in embryonic tissues where peroxisomes had not thus far been recognized, i.e., adrenal and pancreatic parenchyma, choroid plexus, neuroblasts of cranial and spinal ganglia and myenteric plexus, and chondroblasts of certain skeletal structures. In other tissues, i.e., gut epithelium and neuroblasts of some CNS areas, they were identified earlier than previously. In select CNS areas, ultrastructural catalase cytochemistry allowed identification of actively proliferating organelles at early developmental stages in several cell types. Our data show that in most organs maturation of peroxisomes parallels the acquirement of specific functions, mainly related to lipid metabolism, thus supporting an involvement of the organelles in tissue differentiation
Regional and ultrastructural immunolocalization of copper-zinc superoxide dismutase in rat central nervous system
No full textWe examined the distribution of copper–zinc superoxide dismutase (CuZn-
SOD) in adult rat central nervous system by light and electron microscopic immunocytochemistry,
using an affinity-purified polyclonal antibody. The enzyme appeared to be exclusively
localized in neurons. No immunoreactivity was seen in non-neuronal cells. The
staining intensity was variable, depending on the brain region and, within the same region,
on the neuron type. Highly immunoreactive elements included cortical neurons
evenly distributed in the different layers, hippocampal interneurons, neurons of the reticular
thalamic nucleus, and Golgi, stellate, and basket cells of the cerebellar cortex. Other
neurons, i.e., pyramidal cells of the neocortex and hippocampus, Purkinje and granule cells
of the cerebellar cortex, and the majority of thalamic neurons, showed much weaker staining.
In the spinal cord, intense CuZnSOD immunoreactivity was present in many neurons,
including motor neurons. Pre-embedding immunoelectron microscopy of the neocortex,
hippocampus, reticular thalamic nucleus, and cerebellar cortex showed cytosolic and nucleoplasmic
labeling. Moreover, single membrane-limited immunoreactive organelles identified
as peroxisomes were often found, even in neurons that appeared weakly stained at
the light microscopic level. In double immunogold labeling experiments, particulate CuZn-
SOD immunoreactivity co-localized with catalase, a marker enzyme for peroxisomes, thus
demonstrating that in neural tissue CuZnSOD is also present in peroxisomes
Immunohistochemical localization of peroxisomal enzymes during rat embryonic development
No full textPeroxisomes are cytoplasmic organelles involved in a variety of metabolic
pathways. Thus far, the morphological and biochemical features of peroxisomes have been
extensively characterized in adult tissues. However, the existence of congenital peroxisomal
disorders, primarily affecting tissue differentiation, emphasizes the importance of
these organelles in the early stages of organogenesis. We investigated the occurrence and
tissue distribution of three peroxisomal enzymes in rat embryos at various developmental
stages. By means of a highly sensitive biotinyl–tyramide protocol, catalase, acyl-CoA oxidase,
and ketoacyl-CoA thiolase were detected in embryonic tissues where peroxisomes
had not thus far been recognized, i.e., adrenal and pancreatic parenchyma, choroid plexus,
neuroblasts of cranial and spinal ganglia and myenteric plexus, and chondroblasts of certain
skeletal structures. In other tissues, i.e., gut epithelium and neuroblasts of some CNS
areas, they were identified earlier than previously. In select CNS areas, ultrastructural catalase
cytochemistry allowed identification of actively proliferating organelles at early developmental
stages in several cell types. Our data show that in most organs maturation of
peroxisomes parallels the acquirement of specific functions, mainly related to lipid metabolism,
thus supporting an involvement of the organelles in tissue differentiation
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Autophagy and Programmed Cell Death Modalities Interplay in HIV Pathogenesis
No full textHuman immunodeficiency virus (HIV) infection continues to be a major global health challenge, affecting 38.4 million according to the Joint United Nations Program on HIV/AIDS (UNAIDS) at the end of 2021 with 1.5 million new infections. New HIV infections increased during the 2 years after the COVID-19 pandemic. Understanding the intricate cellular processes underlying HIV pathogenesis is crucial for developing effective therapeutic strategies. Among these processes, autophagy and programmed cell death modalities, including apoptosis, necroptosis, pyroptosis, and ferroptosis, play pivotal roles in the host-virus interaction dynamics. Autophagy, a highly conserved cellular mechanism, acts as a double-edged sword in HIV infection, influencing viral replication, immune response modulation, and the fate of infected cells. Conversely, apoptosis, a programmed cell death mechanism, is a critical defense mechanism against viral spread and contributes to the depletion of CD4+ T cells, a hallmark of HIV/AIDS progression. This review aims to dissect the complex interplay between autophagy and these programmed cell death modalities in HIV-induced pathogenesis. It highlights the molecular mechanisms involved, their roles in viral persistence and immune dysfunction, and the challenges posed by the viral reservoir and drug resistance, which continue to impede effective management of HIV pathology. Targeting these pathways holds promise for novel therapeutic strategies to mitigate immune depletion and chronic inflammation, ultimately improving outcomes for individuals living with HIV
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