Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of crocidolite and chrysotile fibres on lavaged peritoneal macrophages have been studied by both scanning (SEM) and transmission (TEM) electron microscopy. SEM provided little information (as the surface topography did not reflect the underlying cytoplasmic organization) except that it showed that individual macrophages often partially engulfed many long fibres in a random fashion. TEM revealed the fibres in and protruding from membrane-bound vacuoles, free in the cytoplasm and penetrating the nucleus. The cellular distribution of the fibres is discussed in terms of the cytotoxic nature of the fibres and their ability to produce a selective release of enzymes from the macrophages.
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PMID:An ultrastructural study of the effects of asbestos fibres on cultured peritoneal macrophages. 627 74

The plasma membrane receptor for GnRH in bovine anterior pituitaries has been solubilized with the cholic acid derivative detergent 3([3-cholamidopropyl)dimethylammonio]propane sulfonate. The soluble receptor in the supernatant from a 100,000 x g x 90 min centrifugation displays high affinity, saturability and specific binding to the agonist, [DA1a6,N alpha MeLeu7, Pro9-NEt]-GnRH. The dissociation constant, KD, for the soluble receptor is 0.56 +/- 0.07 nM (mean +/- SEM) and the number of sites, Ro, is 85 +/- 17 fmols/mg protein. For the membrane-bound receptor the KD is 0.50 +/- 0.04 nM and Ro is 300 +/- 18 fmols/mg protein. The relative potencies of GnRH and the potent antagonist, [Ac-delta 3Pro1,pFDPhe2, DTrp3,6]-GnRH are similar for both the soluble and membrane-bound receptor.
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PMID:Solubilization of the gonadotropin-releasing hormone receptor from bovine pituitary plasma membranes. 629 98

To characterize the production of stem cell factor (SCF, the ligand for the c-kit receptor protein) and its regulation by inflammatory cytokines and glucocorticoids, primary marrow stromal fibroblasts were isolated from normal individuals and two patients with Diamond-Blackfan anemia. Unstimulated normal marrow stromal fibroblasts constitutively expressed a low level of SCF mRNA (9 +/- 2 copies/cell [mean +/- SEM]), continually secreted soluble SCF into the supernatant of 1- to 5-day-old cultures (0.16 +/- 0.02 to 0.73 +/- 0.04 ng/mL per 10(6) cells, respectively), and expressed membrane-bound SCF. Stimulation with interleukin-1 beta (IL-1 beta) only modestly increased SCF mRNA levels, soluble SCF production at 24 hours, and membrane-bound SCF. In comparison, hydrocortisone or tumor necrosis factor alpha (TNF-alpha) exposure increased SCF mRNA levels 3.5- to four-fold above controls, but with different kinetics. The peak TNF-alpha effect was at 6 hours, with return to near control levels at 24 hours, whereas hydrocortisone induced maximal mRNA increases at 12 to 18 hours, and the levels remained high at 24 hours. Similarly, a sustained increase in soluble SCF production was detected during 1 to 5 days of hydrocortisone exposure (0.27 +/- 0.03 to 1.10 +/- 0.08 ng/mL per 10(6) cells), while TNF-alpha stimulation modestly increased the production of soluble SCF in 24-hour cultures only. Unstimulated normal marrow fibroblasts expressed predominantly the long species of alternatively spliced SCF mRNA, and the relative amounts of long and short mRNAs did not change after stimulation with IL-1 beta, hydrocortisone, or TNF-alpha. SCF production by marrow stromal fibroblasts from a symptomatic patient with Diamond-Blackfan anemia was equivalent to simultaneously studied normal marrow fibroblasts. In contrast, marrow fibroblasts from a Diamond-Blackfan anemia patient in untreated hematologic remission constitutively expressed high levels of SCF mRNA (21 +/- 4 copies/cell) and soluble protein (0.40 ng/mL per 10(6) cells at 24 hours). Together, these observations suggest that SCF is constitutively produced by fibroblasts in the human marrow microenvironment and that hydrocortisone induces a modest but sustained increase in SCF gene expression and protein production, compared to only a transient increase induced by TNF-alpha. In addition, these findings support the hypothesis that endogenous or corticosteroid-induced increases in the production of SCF could play a physiologic role in the clinical improvement of congenital anemia.
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PMID:Stem cell factor production by human marrow stromal fibroblasts. 754 39

Intercellular adhesion molecule-1 (ICAM-1) is a membrane-bound molecule that is primarily involved in cell-cell adhesive interactions of the immune system. The levels of soluble ICAM-1 (s-ICAM-1) shed into the circulation were studied in the sera of patients with systemic lupus erythematosus (SLE) by an enzyme linked immunosorbent assay. Serum concentrations of s-ICAM-1 were significantly increased in 61 patients with SLE compared to 51 controls (mean +/- SEM: 564 +/- 30 versus 348 +/- 17 ng/ml, p < 0.0001) and 41% of patients had higher serum levels than the normal cut off value of 584 ng/ml. Among the various clinical manifestations, skin involvement was significantly associated with high serum levels of s-ICAM-1. Individual values of serum s-ICAM-1 concentrations in patients with SLE correlated significantly with two different disease activity indices, as well as with the erythrocyte sedimentation rate and serum levels of soluble interleukin-2 receptors, but not with serum levels of anti-dsDNA antibodies or C4. No significant differences in s-ICAM-1 levels were found between patients receiving immunomodulatory treatment and those who were not. These findings suggest that s-ICAM-1 measurement may serve as an additional serologic marker of disease activity in patients with SLE. Further studies to determine whether increased s-ICAM-1 shedding has any pathogenetic significance or biological role in SLE are warranted.
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PMID:Increased levels of intercellular adhesion molecule-1 in the serum of patients with systemic lupus erythematosus. 790 80

Loss of net ultrafiltration capacity is an important complication in long-term continuous ambulatory peritoneal dialysis (CAPD). It has been reported in animal studies that the drained volumes after a dwell period were larger when amphotericin B had been given intraperitoneally. In this study the effect of intraperitoneally administered amphotericin B on fluid kinetics was evaluated in 3 CAPD patients. The first patient lost 2.5 kg body weight during the first 4 days of treatment, whereas the net ultrafiltration in the second patient was higher in the treatment period compared with the nontreatment period (750 +/- 38 mL/day vs 438 +/- 34 mL/day (mean +/- SEM), p < 0.0001). In the last patient it can be demonstrated that the increase in the net ultrafiltration was caused by an increase in the transcapillary ultrafiltration (570 vs 454 mL/4 hours), but that lymphatic absorption was not different (251 vs 265 mL/4 hours). The higher transcapillary ultrafiltration capacity is probably caused by an increase in the hydraulic permeability. It is likely that this phenomenon is governed by the interaction of amphotericin B with membrane-bound cholesterol leading to the formation of transcellular pores. However, the administration of amphotericin B caused a chemical peritonitis, probably due to its solvent, sodium desoxycholate. Therefore, before amphotericin B can be used for the treatment of CAPD patients with ultrafiltration failure, further investigations are necessary to obtain a solvent for amphotericin B that is nontoxic and causes no chemical peritonitis.
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PMID:The effect of amphotericin B on fluid kinetics and solute transport in CAPD patients. 810 4

Following lymphocyte activation a soluble form of TAC antigen is released. This soluble molecule (soluble interleukin-2 receptor, SIL-2R) seems to corresponds to a truncated extracellular part of the membrane-bound TAC antigen, being smaller than its cellular counterpart. SIL-2R was determined and correlated with PMN elastase levels in the seminal plasma of 79 adult men having different concentrations of PMN elastase (0-700 micrograms/L). The normal level of SIL-2R was detected in the seminal plasma of 15 healthy men. The mean +/- SEM was 101 +/- 29 units/mL. The relation between PMN elastase in human seminal plasma as an index for the state of lymphocyte activity and the sperm motility is also investigated.
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PMID:Determination of soluble interleukin-2 receptor in human seminal plasma. 842 May 1

The ultrastructure of the early chick embryo was investigated, using scanning (SEM) and transmission electron microscopy (TEM). Eggs were obtained from the shell gland by injecting hens intravenously with a synthetic prostaglandin or arginine vasopressin. Embryos were examined during late cleavage (stages IV-VI, Eyal-Giladi and Kochav, '76), formation of the area pellucida (stages VII-XI), and formation of the hypoblast (stages X-XIV). SEM highlighted the reduction in cell number at the underside of the embryo during formation of the area pellucida although it became apparent that the thickness of the embryo is not reduced to a single layer of cells at stage X. In addition, blastomeres at the perimeter of embryos (stages V-VI) project filopodial extensions onto a smooth membrane that separates the sub-embryonic cavity from the yolk. During hypoblast formation, epiblast cells generate stellate projections at their basal aspect, thus providing a meshwork for the advancing secondary hypoblast cells. By stage XII the epiblast was one cell thick and reminiscent of a columnar epithelium when viewed transversely. Cells of the deep portion of the posterior marginal zone were distinguished morphologically in the stage XII embryo by their many cell surface projections and ruffled appearance. Blastomeres at the perimeter of stage V-VI embryos projected filopodial extensions onto a smooth membrane which separates the sub-embryonic cavity from the yolk. This membrane is presumed to be confluent with the cytolemma. Evidence is presented demonstrating the presence of intracellular membrane-bound droplets which are hypothesised to contain sub-embryonic fluid.
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PMID:Early development of the chick embryo. 844 61

An important role in O2 sensing has been assigned to microsomal and membrane-bound b-type cytochromes which generate regulatory reactive O2 species (ROS). Recently, ROS have been shown to suppress the in vitro synthesis of erythropoietin (Epo). We investigated the potential of the antioxidant vitamins A, E and C to enhance renal and hepatic Epo production. Renal effects were studied in isolated serum-free perfused rat kidneys. In control experiments without antioxidant vitamins, Epo secretion amounted to 441 +/- 23 mU/g kidney (mean +/- SEM, N = 5) during the three hour period of hypoxic perfusion (arterial pO2 35 mm Hg). Epo secretion significantly increased to 674 +/- 92 mU/g kidney (N = 7) when vitamins A (0.5 microgram/ml), E (0.5 microgram/ml) and C (10 micrograms/ml) in combination were added to the perfusion medium. The effects of the single vitamins were studied in Epo-producing hepatoma cell cultures (lines HepG2 and Hep3B). Vitamin A induced a dose-dependent increase (half-maximal stimulation at 0.2 microgram/ml) in the production of immunoreactive Epo during 24 hours of incubation (such as 680 +/- 51 U Epo/g cell protein in HepG2 cultures with 3 micrograms/ml retinol acetate compared to 261 +/- 15 U/g in untreated controls; N = 4). In contrast, vitamin E (tested from 0.05 to 500 micrograms/ml) and vitamin C (tested from 2 to 200 micrograms/ml) did not increase Epo production in hepatoma cell cultures. Thus, while vitamins E and C may have the potential to protect cells from oxidative damage, vitamin A exerts a specific stimulation of Epo production. Preliminary evidence suggests that this effect of vitamin A involves increased mRNA levels of hypoxia-inducible factor 1 alpha (HIF-1 alpha).
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PMID:Effects of antioxidant vitamins on renal and hepatic erythropoietin production. 902 29

Adhesion molecules mediate the extravasation of leukocytes and their accumulation in inflamed tissues. In the present study, serum concentrations of the selectin (sP- and sE-selectin) and immunoglobulin supergene family (sICAM-1 and sVCAM-1) of adhesion molecules were measured in 93 patients with inflammatory bowel disease (Crohn's disease, n = 65; ulcerative colitis, n = 28) and 58 age-matched normal controls. sP-selectin serum concentrations (mean +/- SEM ng/ml) of patients with Crohn's disease (399 +/- 33 ng/ml) and ulcerative colitis (385 +/- 42 ng/ml) were increased (P = 0.0067 and P = 0.0193, respectively) compared to controls (251 +/- 33 ng/ml). In contrast, E-selectin serum levels of patients with Crohn's disease (58 +/- 5 ng/ml) and ulcerative colitis (64 +/- 12 ng/ml) were not significantly higher than those of controls (53 +/- 5 ng/ml). sICAM-1 serum concentrations of patients with Crohn's disease (420 +/- 19 ng/ml) and those with ulcerative colitis (375 +/- 40 ng/ml) were elevated (P = 0.0001 and P = 0.0473, respectively) compared to controls (297 +/- 8 ng/ml). Further, sVCAM-1 levels of patients with Crohn's disease (664 +/- 43 ng/ml) and ulcerative colitis (963 +/- 162 ng/ml) were increased (P = 0.0222 and P = 0.0121, respectively) compared to controls (510 +/- 31 ng/ml). With few exceptions, serum levels of soluble adhesion molecules were not significantly correlated to disease activity indices or disease localization. Elevated circulating selectin and immunoglobulin supergene type adhesion molecules may compete with membrane-bound forms for their cognate ligands and thereby limit the rolling and stable adhesion of leukocytes.
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PMID:Elevated serum concentrations of soluble selectin and immunoglobulin type adhesion molecules in patients with inflammatory bowel disease. 925 Aug 94

Ultrastructural changes of the tegument of adult liver flukes, Opisthorchis viverrini, after in vitro incubation in Minimal Essential Medium containing 0, 0.1, 1.0 and 10.0 micrograms/ml of anthelminthic praziquantel for 5, 15, 30, 45 and 60 minutes were investigated by scanning (SEM) and transmission (TEM) electron microscopy. SEM observations showed that the surface damage was composed of blebbing due to the swelling of microvilli, followed later by the disruption of these structures to form lesions that caused the erosion and desquamation of the surface. Sensory papillae, by contrast, appeared relatively unaffected. The surface changes could be observed at all doses but the extent of damage increased with increasing duration of incubation and concentration of the drug. The ventral as well as the dorsal surfaces exhibited similar change, whereas the anterior part tended to be damaged less than the posterior part. Under TEM observations, the earliest sign of changes was the depolymerization of the microtrabecular network in scattered foci, which resulted in the formation of non-membrane-bound vacuoles under microvilli. The basal infoldings also became dilated, and some turned into membrane-bound vacuoles in the basal zone. Subsequently, microvilli became enlarged, and eventually formed blebs that later rupture to form lesion spots as observed in the SEM. Finally, the microtrabecular network in all regions broke down, creating vacuoles of various sizes throughout the tegument, leading to its total disintegration and detachment. The sequence of morphological changes was generally similar at all doses; however, the changes occurred faster at the higher doses and the longer incubation times. In addition, at the longer durations myofilaments in most muscle cells also became depolymerized, while microtubules were unchanged by the drug. Therefore, it is possible that praziquantel, through its induction of Ca2+ influx, causes depolymerization of the microtrabecular network that leads to the vacuolization, swelling, blebbing, and eventually the disruption and detachment of the tegument, and the breakdown of myofilaments in the muscle cells.
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PMID:Opisthorchis viverrini: effect of praziquantel on the adult tegument. 927 94


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