Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

---

Query: EC:3.2.1.36 (hyaluronidase)
4,606 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A procedure for dissociation of the guinea pig pancreas into individual cells is described which employs enzymatic digestion with pure collagenase, chymotrypsin, and hyaluronidase, utilizes an interposed chelation of divalent cations by EDTA, and is terminated by gentle shearing. Yields of cells are 50-60%, based on DNA recovered. The population comprises approximately 95% exocrine cells, the remainder consisting of endocrine, duct, and vascular endothelial cells. The exocrine cells, though spherical, retain the structural attributes of their in situ counterparts, including differentiation of the plasmalemma into zones corresponding to the former apical and basal plasmalemma, polarized distribution of organelles indicated by fields of zymogen granules in the cytoplasm underlying the former apex, central location of the Golgi complex, and placement of the rough endoplasmic reticulum and nucleus in the former basal pole of the cell. Electron microscope study of the effects of individual treatments used during dissociation indicates that digestion of basement membrane and collagen is solely due to collagenase activity and that separation of desmosomes (and possibly of zonulae adherentes) results only from exposure to low [Ca(++)] and EDTA and is not effected by the enzymes used. Gap junctions are resistant to enzymes and EDTA; tight junctions resist enzyme treatment but undergo rearrangement upon exposure to EDTA. Both junctions require mechanical shear for complete cell separation. Neither chymotrypsin nor hyaluronidase produces visible alterations in stromal or junctional elements. Dissociation requires the concerted action of enzymes, chelation of divalent cations, and mechanical shear, since the individual treatments are alone ineffective.
...
PMID:Studies on dispersed pancreatic exocrine cells. I. Dissociation technique and morphologic characteristics of separated cells. 437 77

The dye, triethyl-carbocyanin DBTC, was tested for differential staining of cartilage structures. Femoral head articular cartilage from neonatal rats was processed for histology to demonstrate the interlacunar network. Sections of glycol methacrylate (GMA) embedded cartilage were stained at pH 2.8, 5.4, 6.1 and 8.0 to determine the optimal staining conditions. Only at pH 6.1 were all cartilage structures stained and the best contrast achieved. Streptomyces hyaluronidase, chondroitinase ABC, pepsin, trypsin, and pronase digestions were carried out prior to staining at pH 6.1 to evaluate the selectivity of the stain. Undigested chondrocyte nuclear chromatin stained dark purple; staining intensity was reduced slightly by pepsin or trypsin digestion. Undigested chondrocyte cytoplasm stained light blue but stained purple after hyaluronidase digestion. Undigested extracellular matrix stained light violet; staining was almost entirely eliminated by chondroitinase ABC digestion, was unaffected by hyaluronidase, and was either unaffected or increased after proteinase digestion. Staining of a narrow zone of matrix adjacent to the network was prevented by proteinase digestion while the network element appeared as a thin dark line. The network appears to be a trilaminar structure; a core element of hyaluronic acid and protein surrounded by a protein sheath. Triethyl-carbocyanin DBTC staining of cartilage offers slightly more selectivity and contrast than methylene blue, toluidine blue or safranin O. At pH 6.1, DNA, perhaps RNA, and hyaluronic acid stained deep purple; chondroitin sulfate, light violet; protein (collagen), stained very light violet if at all.
...
PMID:Staining glycol methacrylate embedded cartilage with triethyl-carbocyanin DBTC ("ethyl-stains all") with special reference to the interlacunar network. 608 77

A method for the direct transfection of polyoma viral DNA and polyoma-plasmid recombinant DNA into the liver or spleen of newborn or adult mice was developed. Calcium phosphate-precipitated DNA was injected directly into mouse organs in combination with hyaluronidase and collagenase. Transfected DNA was shown to replicate at moderate efficiency, relative to direct infection of organs with virus. Transfection with viral DNA rapidly led to an acute infection. A polyoma-bacterial plasmid recombinant DNA also was shown to replicate when transfected into mice. With this plasmid, however, genomic-length polyoma DNA rapidly recombined away from the bacterial component and replicated as viral DNA. This method should allow the direct determination of the biological activity of a cloned DNA within a mouse organ.
...
PMID:Direct transfection of viral and plasmid DNA into the liver or spleen of mice. 609 3

Colonic epithelial cells from male Sprague-Dawley rats were isolated by incubating everted colon with hyaluronidase suspended in Puck's saline F with an average cell yield of 120 x 10(6). These cells were fractionated by discontinuous Ficoll gradient and by short-term cell culture techniques. Centrifugation of isolated cells on discontinuous Ficoll gradient (15-35%) yielded populations differing in their proliferative activity. Additionally, a short-term cell culture technique was standardized to fractionate these cells according to their proliferating activity as judged by their DNA synthesis and thymidine kinase activity. Viability of these cells were judged by trypan blue exclusion, capacity to oxidize glucose and incorporation of precursors into protein DNA, RNA and glycoproteins. These fractionated cells were examined and identified by cytological studies. Cells showing proliferative activity sedimented at heavier regions of the Ficoll gradient, and the majority of these cells attached to the surface under conditions of short-term culture. Columnar mature absorptive cells and mucus-secreting goblet cells that showed very little proliferative activity sedimented at lighter zones of the Ficoll gradient and a major portion of these cells failed to attach by the cell culture method.
...
PMID:Characterization of rat colonic epithelial cell populations. 616 93

A procedure for dissociation of the nasal salt glands of the domestic duck, Anas platyrhynchos, into suspensions of individual cells has been developed. This technique employs enzymatic digestion with collagenase, hyaluronidase, and chymotrypsin; divalent cation chelation with EDTA; and gentle mechanical dispersion. Average cellular yields of 39 and 26% based on DNA recovered were obtained from the glands of freshwater- and saline-adapted ducks, respectively. Epithelial secretory cells comprised 60-80% of the cell suspensions with the remainder of the populations consisting of endothelial cells, fibroblasts, and blood cells. The dissociated cells were viable as judged by trypan blue exclusion (80-100%, maintenance of ultrastructural integrity, and retention of responsiveness to secretagogues and metabolic inhibitors. Methacholine chloride (0.5 mM) stimulated oxygen consumption by suspensions of both freshwater- and saline-adapted cells, whereas ouabain (0.05 mM) abolished the methacholine-stimulated respiratory response. These cell suspensions provide a promising system for the in vitro study of secretory mechanisms in the avian salt gland.
...
PMID:Dissociation of avian salt gland: separation procedures and characterization of dissociated cells. 624 10

An enriched fraction of human decidual cells that synthesizes and releases human PRL (hPRL) was obtained by isopycnic centrifugation of collagenase- and hyaluronidase-dispersed cells through Percoll. The cells that synthesized and released hPRL banded at a density of 1.017-1.045 g/ml, an area of the gradient comprising only a small percentage of the total decidual DNA. The enriched cells formed distinct colonies in culture and contained hPRL, as evidenced by indirect immunofluorescent staining with anti-PRL serum. Plated at a density of 5.0 x 10(5) cells/well, the cells produced hPRL at a mean rate of 8.1 +/- 1.1 ng/microgram DNA . 24 h (mean +/- SD) for 8 days. Like decidual explants, the enriched cells responded to phospholipase A2 (0.1 U/ml) with a 54% decrease in hPRL release and to placental conditioned medium (0.5 mg protein/ml medium) with a 62% increase. Insulin (8.3 x 10(-7) M), progesterone (10(-5) - 10(-12) M), and estradiol (10(-5) - 10(-12) M) did not affect hPRL release over 6 days. These results indicate that enriched PRL-releasing cells, obtained by the isopycnic centrifugation of collagenase- and hyaluronidase-dispersed cells, are a useful model for the study of the synthesis and release of PRL.
...
PMID:Characterization of the synthesis and release of prolactin by an enriched fraction of human decidual cells. 630 Jan 79

An enriched fraction of human placental cells that synthesize and release both placental lactogen (hPL) and hCG was obtained by isopycnic centrifugation of collagenase/hyaluronidase-dispersed cells through a density gradient of 40% Percoll. The enriched cells, which banded at a density of approximately 1.01 g/ml, comprised 10-15% of the total DNA. During the first 24 h after attachment, the cells released 50-250 ng hPL and 4-10 mIU hCG/10(6) cells. Thereafter, the rate of hPL release decreased, while the rate of hCG and [35S]trichloroacetic acid-precipitable protein release remained constant. The enriched cells responded to phospholipase A2, low extracellular calcium, and (Bu)2cAMP in a manner similar to that of placental explants. Phospholipase A2 (0.1 and 1 U/ml) stimulated hPL release by 270% and 568%, respectively, and low extracellular calcium (0-0.18 mM) stimulated hPL release by 48%. (Bu)2 cAMP (1 mM) stimulated hCG release by 42%, but had no effect on hPL. Estradiol (10(-5)-10(-12) M) and progesterone (10(-5)-10(-10) M) had no effect on the synthesis and release of either hPL or hCG over a 6-day period. In addition, insulin (8.3 X 10(-7) M) and changes in medium glucose content (0-5 mg/ml) had no effect on hPL release over a 72-h period. Since the enriched trophoblast cells respond to provocative stimuli in a manner similar to that of explants and placental fragments, this cell population is a useful model system for investigations of the cellular mechanisms of hPL and hCG release.
...
PMID:Characterization of the synthesis and release of human placental lactogen and human chorionic gonadotropin by an enriched population of dispersed placental cells. 630 87

Multi-alveolar mammary structures (mammary lobules) were prepared from mammary glands of pseudopregnant rabbits by controlled digestion with collagenase and hyaluronidase. The overall rate of fatty acid synthesis and the proportion of milk-specific fatty acids (C8:0 and C10:0) synthesized by these lobules when cultured with insulin, corticosterone and prolactin were measured. Maximum response to physiological concentrations of prolactin (1.1 or 2.2 nmol/l) occurred in the presence of insulin (1.7 mumol/l) and corticosterone (0.58 mumol/l). In general, the results obtained on the effect of progesterone were negative. Though explants showed a ninefold greater response to prolactin per mg DNA than did mammary lobules, the latter have the advantage of being easily prepared for culture in large numbers. Reduction to below 500 microns diameter and culture in conditions which allow cell outgrowth onto plastic limited their response to prolactin. The probable roles of membrane damage by digesting enzymes and of tissue architecture in limiting prolactin response are discussed.
...
PMID:Milk-fat synthesis by lobules prepared from rabbit mammary gland: response to insulin, corticosterone, prolactin and progesterone. 634 42

Transfection is a technique for inducing transformation of normal fibroblasts (NIH 3T3) with DNA (oncogenes) from human tumors. Our goal was to determine if these transformed cells expressed antigens associated with malignancy. NIH 3T3 cells were transfected with DNA fragments from a human acute lymphocytic leukemia (ALL 1-69), and transformed colonies were selected for growth in soft agar. Transfected cells containing human DNA sequences demonstrated by Southern blot analysis were used to immunize Balb/C mice. Monoclonal antibodies were produced and screened for binding to the parental leukemia (ALL 1-69), transfectant (17(2], and 3T3 cells in an enzyme-linked assay. A monoclonal antibody (IgM kappa) designated 17-9H3 bound to ALL 1-69 and secondary transfectant 17(2) but not to NIH 3T3 plasma membranes. Immunoperoxidase staining confirmed this binding pattern and demonstrated that the antigen was expressed on the cell surface. Expression of the antigen by transfectants directly correlated with the presence of a single 6.1 kilobase human DNA sequence. The antibody binding site of the antigen was inactivated by trypsin, glucosidase, and hyaluronidase. Binding of the 17-9H3 antibody was selective for acute lymphocytic leukemias (5/8) and osteogenic sarcomas (33/36), although other tumor types did demonstrate significant binding by immunoperoxidase staining. The majority of normal tissues did not bind 17-9H3 with the exception of some metabolically active cells (renal tubular epithelium, secretory epithelial cells, and cardiac smooth muscle), germ cells, Leydig cells of the testes, and some lymphoid cells. Monoclonal antibodies to oncogene-associated antigens may be potentially useful for cancer diagnosis and therapy and as probes for oncogene isolation.
...
PMID:A novel approach to production of antitumor monoclonal antibodies: antibody to a cell surface glycoprotein associated with transformation by a human oncogene. 637 59

Five strains of obligately anaerobic, pectin-fermenting spirochetes were isolated from the subgingival plaque of humans. The strains produced two extracellular enzymatic activities that functioned in pectin degradation. One of these enzymatic activities was pectin methylesterase (EC 3.1.1.11), and the other was pectate lyase (EC 4.2.2.2) of the endo type. The data indicate that the cumulative action of these two enzymatic activities brought about depolymerization of pectin in spirochete cultures. Pectin- or polygalacturonate-degrading hydrolases were not detected. A cell-associated lyase activity that catalyzed polygalacturonate breakdown was present in one of the spirochete strains. In addition to pectin, the isolates utilized polygalacturonic, glucuronic, or galacturonic acid as fermentable substrate but did not neutral sugars, amino acids, or other substrates tested. Although the oral spirochetes did not ferment hyaluronic acid, one of the strains grew in coculture with a hyaluronidase-producing Peptostreptococcus strain in a medium containing hyaluronic acid as fermentable substrate. Two of the isolates were identified as Treponema pectinovorum strains on the basis of their substrate utilization pattern, end products of fermentation, other phenotypic characteristics, and the guanine-plus-cytosine content of their DNA. Even though the pectinolytic isolates were specialized with respect to the fermentable substrates they utilized, they appeared to compete successfully with other microorganisms in their habitat.
...
PMID:Pectinolytic enzymes of oral spirochetes from humans. 638 18


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>

---