Atrial septation. II. Formation of the foramina secunda in the chick.
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Animals↗
Biomedical subjects
M J Hendrix
Publications and source records attributed to M J Hendrix.
Production and characterization of a monoclonal antibody to chicken type I collagen.
We have shown that lymphocyte-myeloma cell hybridization can be used to produce large amounts of extremely high-titer specific antibodies against type I collagen, a macromolecule normally of low immunogenicity. In a passive hemagglutination assay the antibody had a high titer against chicken type I collagen but showed no activity against chicken type II or rat type I collagen. By using a two-step fluorescence histochemical procedure on sections of embryonic chicken tibia, strong fluorescence was observed in the perichondrium and surrounding connective tissue (known to contain type I collagen) but not over the cartilage (characterized by type II collagen). When used in conjunction with Staphylococcus aureus as a solid phase immunoadsorbant, the antibody was shown to bind to labeled collagen synthesized in vitro by embryonic chicken calvaria.
Animals↗
The patient is a person--and so is the nurse.
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Education, Nursing↗
Atrial septation. I. Scanning electron microscopy in the chick.
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Age Factors↗
In vitro quantification of melanoma tumor cell invasion.
In order to quantify the invasiveness of melanoma tumor cells in vitro, a modification of the amniotic basement membrane (BM) model, described by Liotta et al. (Cancer Letters, 11, 141, 1980), was used in combination with radiolabeled tumor cells. B16-F10 metastatic murine melanoma cells and a derived clone (B16-F10L) were prelabeled with 0.1 muCi/ml of [14C]thymidine for 20-24 h in serum-free medium at 37 degrees C. Following incubation, fetal bovine serum was added to a concentration of 5 per cent, and the cells were allowed to grow to confluency for the next 24-28 h. The labeled cells were seeded onto amniotic membranes situated in Membrane Invasion Culture System (MICS) chambers at a density of 2.5 X 10(4) per well. At various times points, radioactivity of tumor cells that completely traversed the membrane was determined using an under-the-membrane sampling method. The average percent invasion demonstrated by the B16-F10 line was 2.75 per cent, and 3.65 per cent exhibited by the B16-F10L cell line after 48-53 h in vitro. Since it was apparent that some variability in thickness existed among membrane samples, a morphological analysis was performed on five sectors of a three-inch-diameter sample from four different placentae. Differences and similarities in BM thickness within the same sector were noted by this technique and could possibly contribute to some variability observed in tumor cell invasion in this model. Another parameter examined was the proliferation of tumor cells in the upper and lower wells of the MICS chambers. By 48 h, approximately 32.1 per cent of the B16-F10 cell line as well as the clone had replicated in the upper wells associated with the BMs compared with a 32.9 per cent replication in the lower wells, which reaffirmed the viability of the tumor cells under experimental conditions and insured similarly replicating populations of cells. In order to quantify the invasiveness of radiolabeled tumor cells accurately through a biological membranous barrier, the proper concentration of cells must be used, tumor cell heterogeneity should be taken into consideration, the technique of sampling radiolabeled invasive cells should be critically analysed, and thickness of the membranous barrier should all be considered as possible important factors in the quantitative analyses.
Amnion↗
Growth, morphologic, and invasive characteristics of early and late passages of a human endometrial carcinoma cell line (RL95-2).
Two in vitro passages of a human endometrial adenocarcinoma continuous cell line (RL95-2), an early (subcultured less than 30 times) and a late passage (subcultured greater than 200 times) have provided an interesting model to study the growth, morphologic, and invasive properties of endometrial tumors. The early passage, which has been shown to be estrogen-receptor positive, has characteristics closely resembling a primary tumor, whereas the estrogen receptor negative late passage exhibits several features of the metastatic phenotype. Compared to the early passage cells, the late passage cells were less serum dependent, formed foci, demonstrated a faster rate of growth (due to their shorter doubling times), and attained higher saturation densities. The late passage cells also displayed an altered morphology which was accompanied by alterations in the distribution of F-actin. Even though early and late passages showed similar invasive potential in an in vitro invasion assay, the late passage cells, by virtue of their several transformed characteristics, maintain distinctive properties compared with their early passage counterparts.
Actins↗
Human melanoma cell invasion is inhibited in vitro by swainsonine and deoxymannojirimycin with a concomitant decrease in collagenase IV expression.
A 48 h pretreatment of two malignant and invasive human melanoma cell lines with either swainsonine (an inhibitor of Golgi alpha-mannosidase II) or deoxymannojirimycin (a Golgi alpha-mannosidase I inhibitor) resulted in a dose-dependent decrease in the cells' ability to invade a reconstituted basement membrane in vitro. This effect was reversible within 48 h of removing the drugs. Treatment with either drug resulted in both cell lines being more resistant to the cytotoxic effects of the lectin leukoagglutinin (PHA-L) and more sensitive to the lectin concanavalin A which indirectly indicated a change in the cell surface oligosaccharide composition and structure consistent with the known effects of these drugs on N-linked oligosaccharide processing. A 25-33% decrease was noted in the adhesion of treated cells to either a reconstituted basement membrane or human umbilical vein endothelial cell monolayer while no change was measured in the cells' proliferative rates. A correlative decrease was observed, however, in the expression of human type IV collagenase mRNA which was recovered within 48 h of removing the drugs. These results suggest that a correlation exists between the drug-induced changes in the cell surface oligosaccharide composition and structure with a concomitant decrease in the mRNA and secreted levels of type IV collagenase and the ability of these cells to invade.
1-Deoxynojirimycin↗
Profiles of human melanoma cell surface proteins: effects of culturing on two different substrates.
Three human melanoma cell lines of differing invasive and metastatic potentials were cultured on either a plastic surface or a denuded amniotic basement membrane, and alterations in their cell surface proteins, invasive profiles, and the presence or absence of the 69 Kd high-affinity metastasis-associated laminin receptor were examined. Our data indicate that the labeled, precipitable cell surface proteins are different from the three cell lines when they are cultured on the same substrate, and change when the cells are cultured on a different substrate. Furthermore, the invasive potential (as measured in the in vitro Membrane Invasion Culture System) is decreased for all of the cell lines after culturing the cells on a basement membrane matrix compared to a plastic surface. Finally, we show that the 69 Kd high-affinity metastasis-associated laminin receptor can be isolated from all three cell lines cultured on the two different substrates by labeling the cell surface with trinitrobenzene sulfonic acid and immunoprecipitating these targeted proteins.
Culture Media↗
Retinoic acid inhibits human melanoma tumor cell invasion.
The anticancer effects of retinoids have been recognized both in vivo and in vitro; however, little is known about their mechanism of action. Our study evaluated the effects of retinoic acid on the invasiveness of four human melanoma cell lines in vitro and showed a time-dependent inhibition of the ability of these cells to penetrate matrigel-coated filters. The possible mechanisms of action responsible for the anti-invasive effect were further investigated, and the data showed that retinoic acid-treated cells: (a) secreted lower levels of collagenolytic enzymes detected in type IV collagen-containing polyacrylamide gels compared with control cells, which was demonstrated by a decreased ability to degrade [3H]proline-labeled type IV collagen substrate; (b) showed a reduction in PA activity, primarily in the form of tPA, as demonstrated by chromogenic analysis; (c) showed a heterogeneous response with regard to c-myc, c-fos and c-jun mRNA expression, as determined by Northern blot analysis; and (d) demonstrated a decrease in B-actin levels and an increase in vimentin, as demonstrated by Northern blot analysis and SDS-PAGE transblot analysis. Collectively, these data suggest that RA causes an inhibitory effect on tumor cell invasion through a reconstituted basement basement membrane matrix by suppressing type IV collagenolytic activity and PA activity, which is probably triggered through a complex series of oncogene trans-acting factors, ultimately affecting cytoskeletal expression.
Actins↗
Immunohistochemical localization of actinomycin D in human melanoma tumor cells.
Human melanoma tumor colonies and derived cell lines (81-46a) were exposed to Actinomycin D (Act D) in vitro in order to study subcellular sites of drug-cell interaction. Light microscopy of 13 day-old colonies previously treated for 24 hours with 0.01 microgram/ml, 0.1 microgram/ml, and 1 microgram/ml Act D revealed a decrease in colony size and organization, an increase in pyknotic nuclei, and an accumulation of cell debris concomitant with an increase in Act D concentration. The 81-46a cells were treated with 0.1 microgram/ml Act D for 15, 30, and 60 minute intervals, followed by Act D antibodies. Immunofluorescence microscopy revealed both cytoplasmic, vesicular, filamentous, and nuclear variations in drug distribution with increased exposure. Cell viability studies indicated a decrease in viable cells as exposure time to Act D increased.
Cell Line↗
Membrane invasion culture system (MICS).
New methods for studying the invasive properties of malignant neoplasms are being developed continually. The advantages and disadvantages associated with currently available models have been capitalized upon in the development of a new system that is versatile, reliable, fast, and simple to operate. In order for a tumor cell to metastasize, it must be capable of traversing many complex biological barriers. Because treatment metastatic neoplasms poses many problems for the clinician, the elucidation of the invasion process is of vital importance for the successful treatment of malignant disease. We have developed a system for studying the invasive properties of cells that can be performed accurately with relative ease within a short period of time. This versatile system offers extensive applications for studying invasion properties and parameters. Our model is classified as the Membrane Invasion Culture System.
Amnion↗
Impaired and nonimpaired nurses during childhood and adolescence.
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Adult↗
Reduced levels of testosterone and dehydroepiandrosterone sulphate in the serum and synovial fluid of juvenile rheumatoid arthritis patients correlates with disease severity.
OBJECTIVE: The status of androgen levels and their significance in the pathogenesis of juvenile rheumatoid arthritis (JRA) has not been fully investigated. In the present study serum and synovial fluid (SF) from 20 JRA patients (grouped as pre-pubertal and pubertal) were analyzed for their content of testosterone, dehydroepiandrosterone (DHEA) and its sulphated conjugate DHEA-S, progesterone and 17 beta-estradiol. RESULTS: Comparison of the results from JRA patients with that of age-matched controls indicated no significant differences in progesterone and DHEA. Similarly, 17 beta-estradiol levels from the pubertal group were comparable to those of the controls; however, prepubertal patients had no detectable levels of this hormone. DHEA-S values were significantly lower in the pubertal JRA group, 1388.3 +/- 291.8 and 1663.9 +/- 354.1 nmol/l in the serum and SF, respectively (compared to 8206.6 +/- 848.12 in the serum of matching controls). These patients also presented with a much lower testosterone content in their SF than in their serum, 0.09 +/- 0.036 and 0.56 +/- 0.068 nmol/l, respectively (compared to 1.35 +/- 0.146 in the serum of corresponding controls). CONCLUSION: The data presented in this paper demonstrate for the first time an association between low androgen levels and disease in JRA patients. The significance of hypoandrogenicity with respect to the pathogenic mechanisms of arthritic disease and the possible therapeutic strategies that these imply warrants further investigation.
Adolescent↗