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Query: UNIPROT:Q9UIJ5 (
Rec
)
58,342
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Human NK activity is known to be associated with a population of large granular lymphocytes (LGL) exhibiting several immunophenotypic surface markers including Leu-11a (NKP-15), Leu-7 (HNK-1), Leu-3a (T4), and Leu-2a (T8). Based upon correlation with cytolytic activity, Leu-11a is now considered the most specific antigenic marker for human NK cells. Present investigation compared the ultrastructure of cells expressing Leu-11a, Leu-7, Leu-3a, and Leu-2a, both in human peripheral blood lymphocytes (PBL) and the purified LGL fraction. Subcellular cytochemical reactions were investigated in Leu-7+ or Leu-11a+ PBL or LGL and in cells conjugated with K562 targets (indicating NK cytolytic potential). The surface markers, localized with monoclonal antibodies, were detected by immunoelectron microscopy by using direct or indirect avidin-biotin-peroxidase (ABC) or colloidal gold methods. A peroxidase-colloidal gold double-labeling system was used to identify subsets of Leu-7+ or Leu-11a+ cells. Previously described ultrastructural features of LGL including a villous surface, reniform nuclei, low nuclear/cytoplasm ratios, and abundant cytoplasm with vesicles, vacuoles, electron-dense granules, parallel tubular arrays (PTA), or paracrystalline inclusions were associated with Leu-7+, Leu-11a+, Leu-7+/Leu-11a+, Leu-7+/Leu-11a-, and Leu-7-/Leu-11a+ PBL or LGL. Results showed that the Leu-7+/Leu-11a+ cells were the most abundant NK cells in PBL. Lymphocyte subsets with Leu-3a or Leu-2a surface marker showed some ultrastructural features including PTA similar to Leu-7+ cells and Leu-11a+ cells, and their subsets. These T-cells appeared ultrastructurally more similar to the Leu-7+/Leu-11a- subset. Cytochemical studies showed that electron-dense cytoplasmic granules and PTA typical of the Leu-11a+ cells and Leu-7+ cells contained glycoprotein, acid phosphatase, and arylsulfatase. Large cytoplasmic vacuoles were heterogeneous and typically contained electron-dense material with
DAB
reactivity, membranous material, PTA, and/or paracrystalline inclusions. Glycoprotein, acid phosphatase, and arylsulfatase, and peroxidase reactive material were also found in these vacuoles. These features suggested that the vacuoles could be secondary lysosomes. The coexistence of intact PTA or degenerating PTA in the same vacuoles with paracrystalline inclusions suggested that the latter are possibly derived from PTA.
Anat
Rec
1987 Mar
PMID:Immunoultrastructural studies of human NK cells: I. Ultracytochemistry and comparison with T cell subsets. 355 61
An improved method is presented for processing single cells for electron microscopy. Agarose, which has a low (30 degrees C) gelling temperature, was used as an initial embedding medium for single cells (spermatozoa and oocytes) and dissociated cell preparations (luteal cells and spleen cells). Dispersed cells of corpus luteum, spleen, and epididymal spermatozoa were placed in 1.5% agarose after aldehyde fixation. These fixed cells, embedded in agarose, were packed into a dense pellet by centrifugation, postfixed, then embedded in Epon. Mammalian eggs were not centrifuged; instead, they were embedded in agarose discs. Cells embedded in agarose were cooled below 30 degrees C to allow for gelling, then processed for electron microscopy. Because agarose has a low gelling temperature, some heat-labile substances were preserved, as demonstrated by retention of peroxidase activity using the
DAB
histochemical method. The agarose embedding procedure is both rapid and facile, and has proven to be of value in the handling of fragile single cells for electron microscopic studies.
Anat
Rec
1981 Oct
PMID:An improved method for processing single cells for electron microscopy utilizing agarose. 703 63
Superoxide anion production in neutrophils plays an important role in the microbicidal defense system in the body. In this study, isolated rat neutrophils were stimulated experimentally and examined by electron microscopy to determine the site of superoxide production and its subsequent translocation during different cell stimulation time periods. Blood and peritoneal neutrophils were incubated for periods of 5, 10, and 15 min with phorbol 12-myristate 13-acetate (PMA), N-formyl-Met-Leu-Phe (fMLP), and combinations of PMA and cytochalasin B (CB) and fMLP and CB. Ultracytochemical detection of O(2)(-) was performed with the 3, 3'-diaminobenzidine-manganese (
DAB
/Mn) cytochemical method and cationized ferritin (CF) particles were added to stimulation media to monitor endocytotic events that occurred during neutrophil stimulation. Unstimulated neutrophils were devoid of O(2)(-) activity in cytoplasmic granules and at the plasma membrane surface. After 5 min stimulations with PMA, PMA + CB, or fMLP + CB, electron-dense
DAB
/Mn reaction product was detected in small, centrally located tubular compartments within the neutrophils. CF particles which were added to the stimulation media became internalized in endocytotic vesicles after 5 min stimulation; these vesicles were devoid of O(2)(-) activity. At 10 min stimulation with PMA, O(2)(-)-positive granules subsequently fused with each other and translocated to sub-plasma membrane regions where they either contacted the plasma membrane or fused with CF-containing endocytotic vesicles. Little reaction product was observed on the surface of the neutrophils. Spectrophotometric comparison of the stimulatory effects of PMA, fMLP, and fMLP + CB revealed different rates and yields of O(2)(-) production. Results from this study suggest that the O(2)(-)-producing sites of rat neutrophils originate intracellularly and translocate to the plasma membrane surface following stimulation with PMA, PMA + CB, and fMLP + CB, but not with fMLP or CB alone. Furthermore, these compartments appear to possess the ability to fuse with endocytotic vesicles, a process that may be linked to intracellular microbicidal activity in circulating and tissue neutrophils.
Anat
Rec
2000 02 01
PMID:Ultracytochemical study on the localization of superoxide producing sites in stimulated rat neutrophils. 1064 63
This study presents the research on the chemical analysis and genotoxicity of 28 virgin/recycled paper products in food-contact use. In the chemical analysis, paper products were extracted by reflux with ethanol, and analyzed by gas chromatography/mass spectrometry. 4,4'-bis(dimethylamino)benzophenone (Michler's ketone: MK), 4,4'-bis(diethylamino)benzophenone (DEAB), 4-(dimethylamino)benzophenone (
DMAB
) and bisphenol A (BPA) were found characteristically in recycled products. Seventy-five percent of the recycled paper products contained MK (1.7-12 microg/g), 67% contained DEAB (0.64-10 micro g/g), 33% contained
DMAB
(0.68-0.9 microg/g) and 67% contained BPA (0.19-26 microg/g). Although, BPA was also detected in virgin paper products, the detection levels in the recycled products were ten or more times higher than those in the virgin products. The genotoxicity of paper and paperboard extracts and compounds found in them were investigated by
Rec
-assay and comet assay. Of the 28 products tested by
Rec
-assay using Bacillus subtilis, 13 possessed DNA-damaging activity. More recycled than virgin products (75% against 25%) exhibited such activity, which, of the compounds, was observed in BPA, 1,2-benzisothiazoline-3-one (BIT), 2-(thiocyanomethylthio)benzothiazole, 2,4,5,6-tetrachloro-isophthalonitrile, 2,4,6-trichlorophenol (TCP), and pentachlorophenol. The critical toxicant in one virgin paper product was concluded to be BIT. Eight samples with DNA-damaging activity were also tested by comet assay using HL-60 cells; six induced comet cells significantly (five times or higher than the control) without a decrease of viable cells. TCP, BZ, DEAB, and BIT also caused a slight increase in comet cells. In conclusion, we showed that most recycled paper products contain chemicals such as MK, DEAB,
DMAB
, and BPA, and possess genotoxicity. However, the levels of the chemicals in the recycled products could not explain their genotoxic effects.
...
PMID:Chemical analysis and genotoxicological safety assessment of paper and paperboard used for food packaging. 1520 84