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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ultrastructural analysis of the cell surface and of membrane components such as antigens or receptor sites by scanning immunoelectron microscopy (immuno-SEM) has been the subject of extensive investigation during the past few years. We review the various immunologic and cytochemical techniques applied to SEM, which have employed latex particles, viruses, bacteriophages, protein A, ferritin, gold granules, hemocyanin and peroxidase as markers, and the advantages and disadvantages of these techniques. From current data, it is clear that immuno-SEM has much to offer in determining the distribution of specific cell surface sites and in positive and unambiguous identification of cell types in heterogeneous cell populations.
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PMID:Scanning immunoelectron microscopy markers. 22 92

Infection with herpes simplex virus type 1 (HSV-1) induces different morphological changes in different cell lines. This is demonstrated by comparative scanning (SEM and transmission (TEM) electron microscopic investigations of cell cultures prepared under identical conditions. SEM of HSV-1 infected HEp-2 cells reveals a slightly altered cell surface: only the number of the microvilli is reduced. Large amounts of released virions are detectable adhering to the outer plasma membrane. Ultra-thin sections show typical virus maturation steps in the nuclei (formation of nucleocapsids and virus budding from the inner lamella of the nuclear membrane) and in the cytoplasm (egress of enveloped nucleocapsids through membranous structures). HSV-infected primary chick embryo fibroblast (CEF) cells are characterized by crumpled and rough surfaces without virus particles adhering to the membrane. Ultra-thin sections exhibit atypical virus maturation with many unenveloped nucleocapsids within the cytoplasm. The distribution of HSV-induced antigen(s) on the surface of the infected cells is identical in the two cell systems as determined by the peroxidase labelling technique. The c.p.e. (as seen by phase contrast light microscopy) is similar in both HEp-2 and CEF cells: both fusion and rounding up is induced in the infected cells.
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PMID:Differences in the morphology of herpes simplex virus infected cells: I. Comparative scanning and transmission electron microscopic studies on HSV-1 infected HEp-2 and chick embryo fibroblast cells. 23 Feb 92

To determine alpha-fetoprotein (AFP) in human saliva, a highly sensitive sandwich enzyme immunoassay for saliva AFP was developed. AFP standards and saliva samples were added into the wells of a polystyrene plate coated with goat IgG antibody against human AFP. After incubation, the wells were washed and horseradish peroxidase-labelled antibody was added. The enzyme activity specifically bound to the well was assayed using 3,3',5,5'-tetramethylbenzidine and hydrogen peroxide as substrate. The reaction was stopped by addition of 2 M sulphuric acid and the AFP concentration was determined from the absorbance at 450 nm. The minimum detectable concentration was 8 ng/L. The recovery of AFP mixed with human saliva was 91.1-102.4%. The within-assay and between-assay coefficients of variation were 6.5-8.9% and 7.6-10.8%, respectively. The assay correlated well with a radioimmunoassay for human AFP (r = 0.985, n = 13, P less than 0.001). The mean concentration of AFP in normal human saliva was 14.3 ng/L (SEM = 4.9 ng/L, n = 10) and significantly higher levels of saliva AFP were observed in hepatocellular carcinoma patients with positive serum AFP (mean 1367.8 ng/L, SEM 595.4 ng/L, n = 6; P less than 0.001). Strong correlation was observed between saliva AFP and serum AFP (r = 0.978, P less than 0.01, n = 13).
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PMID:Highly sensitive sandwich enzyme immunoassay for alpha-fetoprotein in human saliva. 128 27

From preclimacteric women (n = 10, 45-50 years of age) with gross cystic breast disease, levels of beta-endorphin, estradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, cortisol and prolactin were assayed radiochemically in the breast cyst fluid and in plasma. The beta-endorphin concentration (fmol/ml) was increased more than fourfold in the breast cyst fluid (17.6 +/- 4.6 SEM) than in plasma (4.2 +/- 0.5 SEM). In the breast cyst fluid, estradiol was increased 41-fold (1738.2 +/- 350.5 SEM pg/ml), and progesterone 47-fold (65.47 +/- 8.25 SEM ng/ml) more than in plasma. The significantly increased values of beta-endorphin, estradiol and progesterone in the breast cyst fluid and the identification of beta-endorphin in cyst-lining epithelia demonstrate the local synthesis. Growth factor-like properties of beta-endorphin and estradiol are accountable for the propagation of cystic changes. The autonomic formation and function of beta-endorphin, estradiol and progesterone in cyst compartments can not be related with the levels of luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone and cortisol, which were significantly higher in plasma than in the breast cyst fluid. In the breast cyst fluid, prolactin could not detected to be significantly higher than in plasma. In addition the plasma-concentration of testosterone, androstenedione, thyroxin, triiodothyronine, thyroid-binding globulin, sexual-hormone-binding-globulin could be detected within the normal range. In this study we could demonstrate the synergism of beta-endorphin, steroid hormones and peptide hormones which advance the growth of gross cystic disease of preclimacteric women. Beta-endorphin was also examined by immunocytochemical assays (fluorescence, alkaline phosphatase and horseradish peroxidase method), in 11 women with pure fibrocystic disease, in 7 women with fibrocystic disease combined with a carcinoma in situ and in 15 women with fibrocystic disease combined with invasive carcinoma of the breast. Sections of frozen and paraffin embedded tissue of the same patient were reacted with anti-beta-endorphin antiserum. The immunoreactivity of beta-endorphin was intense in normal, proliferative altered and cyst-lining epithelia of fibrocystic disease and decreased in atypical epithelia and carcinoma cells of the breast. The degree of beta-endorphin staining is related to the degree of cell differentiation. In addition, nuclear receptors for estrogen and progesterone were assayed by peroxidase antiperoxidase technique.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Interaction between beta-endorphin, steroids and peptide hormones in fibrocystic lesions of the female breast]. 164 46

1. In this study, the carbohydrate structure of pure human renin was examined by using various lectins. 2. Pure renin could be separated into three forms by concanavalin A chromatography, a concanavalin A-unbound form, a loosely bound form and a tightly bound form, termed renins A, B and C, respectively. Renins A, B and C accounted for 3, 13 and 84%, respectively, of the purified renin. These forms were all present in individual human plasma and the relative proportions in plasma were 27 +/- 3, 33 +/- 4 and 39 +/- 5% (means +/- SEM) for renins A, B and C, respectively (n = 5). 3. Each form, electroblotted on to the nitrocellulose sheet after gel electrophoresis, was incubated with five peroxidase-labelled lectins, lentil lectin, erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin, Ricinus communis agglutinin and peanut agglutinin. The protein was stained with 4-chloro-1-naphthol. 4. The staining pattern obtained with these lectins was significantly different among the three forms of human renin, confirming that they have different carbohydrate structures. Furthermore, the positive staining of human renin with erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin and Ricinus communis agglutinin was in contrast with the lack of binding of rat renin to these lectins. 5. These results indicate the renal secretion of differently glycosylated multiple forms of human renin. The carbohydrate structure of human renin appears to differ from that of rat renin.
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PMID:Evidence for heterogeneity of glycosylation of human renin obtained by using lectins. 165 42

A sensitive enzyme immunoassay (EIA) micromethod is described which can measure levels of a 14 kDa human brain lectin (HBL) in the cerebrospinal fluid (CSF) of patients submitted to CSF examination. The assay is based on the use of a polyclonal antibody to HBL and the simultaneous application of biotinylated and unlabeled HBL. Biotin was then reacted with a streptavidin-peroxidase (Strep-HRP) conjugate and the bound enzyme quantified with the substrate orthophenylenediamine (OPD). The assay requires only 50 microliters of CSF and is very sensitive: as little as 6 ng/ml of HBL 14 can be detected. In a blind-test screening, the mean (+/- SEM) concentration of the HBL immunoreactive material (HIM) in CSF was determined to be 72.4 +/- 6.6 ng/ml. Our results indicate that EIA measurement of HIM levels in the CSF may find useful applications in elucidating the involvement of HBL in the physiopathology of human nervous system (NS).
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PMID:Human brain lectin immunoreactive material in cerebrospinal fluids determined by enzyme immunoassay (EIA). 179 70

It has been suggested that matrix molecules like fibronectin and laminin influence the differentiation and migration of embryonic cells. We investigated the role of these two glycoproteins in somitogenesis as well as in the differentiation and migration of the avian Wolffian (pronephric and mesonephric) duct. At first, we described essential steps in the development of these two organ anlagen by light microscopy, SEM and TEM. To localize fibronectin and laminin more exactly in the actual stages, we used the indirect immunoperoxidase reaction at the light microscopic level and the peroxidase-antiperoxidase technique at the ultrastructural level. Fibronectin was found at the surface of the unsegmented paraxial mesoderm, increasing in the cranial direction, and in the basal laminae of somites and Wolffian duct. The mesenchymal tip of the duct contains a moderate amount of fibronectin. In the two investigated organ anlagen, laminin was found mainly in the basal laminae. The role of fibronectin and laminin was investigated further by using synthetic peptides that mimic the main cell binding domain of either fibronectin or laminin, and that competitively inhibit their cell surface receptors. Thus, the pentapeptides GRGDS, YIGSR, and for control, SHLVE were micro-injected under the ectoderm of 2-day-old embryos. After treatment with GRDS, the Wolffian duct and the segmental plate are more compact. The rounded cells exhibit only short processes and narrow intercellular spaces. At the side of injection the duct shows a delay in migration. After treatment with YIGSR the Wolffian duct migrated laterally over the somatopleure. The basal laminae seem to be incomplete. SHLVE had no effect. Our results suggest that fibronectin is a prerequisite for the migration of the Wolffian duct, and that laminin probably plays a role in guiding the duct. The epithelialization during somitogenesis and differentiation of the duct is a more complex process involving also fibronectin and laminin.
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PMID:The role of fibronectin and laminin in development and migration of the avian Wolffian duct with reference to somitogenesis. 186 90

A monoclonal antibody-based immunoenzymometric assay (IEMA) for the measurement of human serum growth hormone is described. Two high-affinity and complementary monoclonal antibodies were selected from a panel of 9 obtained upon fusion of SP2/O myeloma cells with spleen cells from a Balb/c mouse immunized against human growth hormone of pituitary origin. One monoclonal antibody was immobilized by attaching it to the walls of microtiter wells and the second was biotinylated. The reaction was quantitated by the addition of streptavidin-peroxidase. The sensitivity of the assay was 0.2 mIU/l and the intra- and interassay coefficients of variation for 4.6 to 46 mIU/l were less than 8.3 and 17.3%, respectively. Cross-reaction with human placental lactogen, human prolactin and rat growth hormone was less than 0.1% (w/w). Comparison of results obtained for 180 routine serum assays by radioimmunoassay and the assay described here had a correlation coefficient of 0.94 with a mean value of 16.3 +/- 1.3 (mean +/- SEM) and 13.3 +/- 1.2 mIU/l, with the IEMA providing values 18% lower than the RIA. The discrepancy emphasizes the necessity of redefining normal ranges before immunometric assays, like the one described, can be used routinely.
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PMID:Monoclonal antibody-based immunoenzymometric assay for serum human growth hormone. 209 41

By the production of microbicidal agents, such as reactive oxygen species, activated PMN are capable of inducing tissue damage in the host. TNF-alpha was recently shown to be a potent activator of PMN oxidative metabolism. To further evaluate the interaction between activated PMN with physiological target cells, the effect of human PMN on cultured bovine aortic and human umbilical vein endothelial cells (EC) upon stimulation with human TNF-alpha was investigated by ultrastructural techniques: Scanning and transmission electron microscopy (SEM and TEM resp.) and ultrastructural detection of H2O2 production. When isolated PMN were added to EC in the presence of recombinant human TNF-alpha (10(3) U/ml) the EC-monolayer was disrupted within 4 h and EC changed their shape by exhibiting a spindle-like structure. PMN were seen in the intercellular spaces. Release of H2O2 was observed at the surface of the PMN plasma membrane, the luminal part of the small intracytoplasmic vacuoles in the PMN as well as in the contact zone between PMN and EC, but not within the EC. Scavengers of reactive oxygen species, such as superoxide dismutase and catalase or D-mannitol failed to block the effect of TNF-alpha-stimulated PMN on EC. In contrast, addition of NaN3 (0.1 mM), an inhibitor of myeloperoxidase activity, almost completely inhibited the disruption of EC-monolayers. Subsequent addition of NaN3-insensitive horseradish peroxidase reconstituted the effect. The results obtained suggest that TNF-alpha-stimulated PMN effectively cause the disruption of EC monolayers by an adherence-dependent mechanism which is mediated by the release of myeloperoxidase. The results may be of major importance for the pathogenesis of inflammatory vascular reactions.
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PMID:Interaction of granulocytes and endothelial cells upon stimulation with tumor necrosis factor-alpha: an ultrastructural study. 209 2

In this study we present evidence for reactivity of pregnancy lymphocytes, but not nonpregnancy lymphocytes, with the progesterone receptor-specific monoclonal antibody mPRI. Using an avidin-biotin peroxidase detection system, we found a nuclear staining in 14.6 +/- 3.7% (mean +/- SEM, N = 27) of pregnancy lymphocytes, while only 0.47 +/- 0.33% (mean +/- SEM, N = 15) of nonpregnancy lymphocytes reacted with the antibody. To characterize the receptor-bearing subset, CD8+ and CD4+ cells were depleted by complement-dependent lysis. Depletion of CD8+ cells was accompanied by 62 +/- 18% loss of progesterone receptor-bearing cells, while depletion of CD4+ cells resulted in a twofold increase in the number of positively staining lymphocytes. In nonpregnancy lymphocytes a 3-day PHA treatment, as well as allogeneic stimulation, resulted in a significant increase in the number of receptor-containing cells. These results suggest that pregnancy, but not nonpregnancy, lymphocytes contain progesterone binding structures, and that these are inducible by mitogenic or alloantigenic stimuli.
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PMID:Reactivity of lymphocytes to a progesterone receptor-specific monoclonal antibody. 210 67


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