Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.21.1 (DNase)
 7,655 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The ovaries taken from the immature female rats primed with PMSG-hCG were digested with collagenase-DNAase solution to obtain the luteal cell suspensions. Luteal cells were then incubated with different doses of hCG, cAMP or progesterone for 1.5 hours. The contents of tyrosine in luteal cell suspensions were determined by thin layer chromatogram using dual-wavelength chromatogram scanner. It was found that the content of tyrosine in rat luteal cell suspensions was 1.41 + 0.24 nmol/L/10(6) cells after one hour incubation. hCG, cAMP and progesterone all could significantly increase the content of tyrosine in the suspensions, suggesting the release of "endogenous tyrosine". The increase of tyrosine was not due to increased transformation of phenylalanine, the precursor of tyrosine, and increased protein synthesis, because both phenylalanine and cycloheximide failed to influence such increase.
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PMID:[The content of tyrosine in rat luteal cell and the changes caused by hCG, cAMP and progesterone]. 254 85

A method is described for the isolation of biliary epithelial cells from rat livers by sequential treatment with EGTA, collagenase-hyaluronidase, trypsin, and deoxyribonuclease I and final separation on a discontinuous Percoll gradient using prekeratin antibodies as an immunohistochemical marker for these cells.
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PMID:The isolation of intrahepatic biliary epithelial cells from normal rat livers. 258 10

To determine whether the production of experimental hepatic metastases in athymic nude mice by human colorectal carcinomas (HCC) correlated with the clinical outcome in patients, we harvested colorectal carcinomas from 82 patients, dissociated the tumors with collagenase and DNase, and injected them into groups of nude mice, either in the flank to assess experimental tumorigenicity or into the spleen to produce experimental metastasis in the liver. Growth in mice was then associated with clinicopathological factors and clinical outcome. Growth of HCC in either the flanks or the livers of nude mice was associated with the time to recurrence in a Wilcoxon analysis. Analysis of the outcome data in a Cox proportional hazards model suggested that there was an interaction between tumorigenicity and metastatic potential of HCC in nude mice and serum CEA concentration in the patient and stage of disease. A univariate analysis indicated that both tumorigenicity and metastatic potential of HCC in nude mice were significantly associated with the serum CEA concentration of the patient but not with the other variables of stage of disease, mucin production, local tissue invasion, state of differentiation, or sex. A subset of 57 patients was operated upon for cure and followed prospectively for up to 61 months. Tumorigenicity and, to a lesser extent, experimental metastatic potential were associated with disease recurrence in 23 of these patients. Seventy-eight % of the subset of patients who were operated upon for cure developed liver metastasis as one site of their progressive disease. Thus, the ability of HCC cells isolated from surgical specimens to grow in athymic nude mice correlates with the development of advanced disease in patients.
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PMID:Metastatic potential of human colorectal carcinomas implanted into nude mice: prediction of clinical outcome in patients operated upon for cure. 258 33

More efficient methods of islet isolation must be developed for islet transplantation to become clinically routine. During collagenase dispersal of human pancreas, an amorphous, viscous, gellike material often develops and entraps large numbers of islets, thereby reducing the yield. When donor human pancreas is minced and treated with collagenase, the gel forms most abundantly if the digestion temperature is less than 35 degrees C and if pH falls below 7.2 +/- 0.2. Gel formation appears to be proportional to warm- or cold-ischemia time and may be related to tissue trauma during collection. Once gel has formed, trapped islets cannot be released by filtration, dilution, DNase, incubation temperature, or pH adjustment. These characteristics suggest that the material is gelatin derived from collagen released enzymatically from pancreatic stroma. We demonstrate that gelation is greatly reduced or eliminated when 1) the incubation medium includes glycerol--a common gelatin solvent--at 5% (vol/vol), 2) the minced tissue-to-total incubation volume ratio is greater than or equal to 1:10, 3) free-islet exposure to pancreatic digestion products is minimized by frequent separation of islets, and 4) collagenase concentration is optimized by titration. Gelation is also minimized by maintaining 5) incubation temperature at 38 +/- 1 degree C and 6) pH in the range 7.7-7.9. Variations in these physical and chemical conditions were analyzed by determining islet yields (stereoscopic microscope counts of serially diluted samples) and by insulin radioimmunoassay of acid alcohol extracts of isolated islets after separation through discontinuous Ficoll gradients. When isolation conditions are optimized as stated, we typically recover 3.3 +/- 1.0 x 10(4) islets/g pancreas, corresponding to greater than 10(6) islets per donor.
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PMID:Factors influencing isolation of islets of Langerhans. 264 35

This study investigated the direct effect of catecholamines, epinephrine (EPI), and norepinephrine (NE) on basal and gonadotropin-releasing hormone (GnRH)-stimulated secretion of luteinizing hormone (LH) from dispersed pig pituitary cells in vitro. Pig pituitaries were dispersed into cells with collagenase and DNAase and then cultured in McCoy's 5a medium containing horse serum (10%) and fetal calf serum (2.5%) pretreated with dextran-coated charcoal for 3 days. EPI and NE did not affect basal LH secretion after 4 h of incubation. When pituitary cells were incubated with EPI or NE (1 microgram/ml) for longer than 30 min, GnRH-stimulated LH secretion was reduced. The degree of this reduction was dependent on EPI and NE, and a concentration of EPI and NE higher than 1 ng/ml and 100 ng/ml, respectively, was needed. L-isoproterenol, a nonselective beta-agonist, also inhibited the LH response to GnRH. Propranolol, a beta-antagonist, blocked the inhibitory effect of EPI, whereas phentolamine, an alpha-antagonist, had no effect. These results suggest that catecholamines, acting by a beta 2-adrenergic receptor, may play a role in the control of the porcine pituitary gonadotrope's response to GnRH.
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PMID:Catecholamine inhibition of luteinizing hormone secretion in isolated pig pituitary cells. 266 85

Calvaria from 20-21 day old fetuses were obtained under sterile conditions and the endo- and exoperiosteum stripped off. Cells were dispersed by sequential collagenase-DNase treatment and suspended in 0.5% low Tm agarose in the presence of DMEM supplement with 10% FCS. After 4-5 days of incubation some 30% of these cells showed active synthesis of metachromatic extracellular matrix. Cells from skin, muscle and periosteum failed to show metachromatic matrix positive colonies to a comparable extent. The phenotypic expression of these cells was determined by analysis of collagen types. Eleven day old cultures were incubated in the presence of [3H]-proline plus beta-aminopropionitrile and ascorbic acid and the collagen extracted analyzed by polyacrylamide electrophoresis of their intact chains or CNBr-derived peptides. The results show that anchorage independence is a requirement for calvaria cells to express type II collagen. Type I collagen was preferentially expressed in monolayer culture or when pre-attached to a substrate before being cultured in agarose. Type II collagen was the predominant collagen when cells were cultured in agarose. Further characterization of cell populations was achieved by isopycnic centrifugation in a percoll gradient. Cell fractions were tested for their collagen phenotype when cultured in agarose. Cells recovered from densities 1.04 g/ml or higher synthesized type II collagen, while cells with densities lower than 1.04 g/ml synthesized mainly type I collagen. Isopycnic centrifugation appears to be a novel method for separation of phenotypically different cells from a heterogeneous population in fetal calvaria. The high density cell fractions may represent a mixture of pre-chondrocytes as well as pluripotential cells.
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PMID:Cells isolated from fetal rat calvaria by isopycnic separation express different collagen phenotypes. 271 31

The effect of cortisol or adrenocorticotropic hormone (ACTH) on basal and gonadotropin-releasing hormone (GnRH)-induced secretion of luteinizing hormone (LH) was studied in vitro using dispersed pig pituitary cells. Pig pituitary cells were dispersed with collagenase and DNAase and then grown in McCoy's 5a medium containing 10% dextran charcoal-pretreated horse serum and 2.5% fetal calf serum for 3 days. Cells were preincubated with cortisol or ACTH before GnRH was added. When pituitary cells were incubated with 400 micrograms cortisol/ml medium for 6 h or longer, increase basal secretion of LH was observed. However, GnRH-induced LH release was reduced by cortisol. The degree of this reduction was dependent on cortisol, and a concentration of cortisol higher than 100 micrograms/ml was needed. Cortisol also inhibited the 17 beta-estradiol-induced increase in GnRH response. ACTH-(1-24), ACTH-(1-39), or porcine ACTH had no influence on GnRH-induced LH secretion. Our results show that cortisol can act directly on pig pituitary to inhibit both normal and estradiol-sensitized LH responsiveness to GnRH.
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PMID:Effect of cortisol or adrenocorticotropic hormone on luteinizing hormone secretion by pig pituitary cells in vitro. 282 56

Functional gastrin-containing tumor cells (GT cells) have been maintained in short-term culture on microporous membranes, and their response to selected agents has been determined. After dispersion of gastrinoma by collagenase-DNAase digestion coupled with mechanical disruption, dispersed cells were depleted in stromal material by selective attachment to a plastic substrate, then cultured for 72 hours on porous cellulose membranes. Cultures contained 68 +/- 5% GT cells with a viability of 92 +/- 2%. Secretin stimulated the rate of gastrin release from cultured GT cells in both a time- and a dose-dependent fashion. To examine the possible involvement of adenylate cyclase- and protein kinase C-mediated mechanisms in regulating gastrin release from the neoplastic GT cells, we evaluated the effects of 8-bromoadenosine 3':5'-cyclic monophosphate (8-BrcAMP; 10(-4) - 10(-2) mol/L), the diterpene forskolin (10(-5) mol/L), 12-0-tetradencanoylphorobol 13-acetate (TPA; 10(-8) - 10(-6) mol/L), and 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD; 10(-8) - 10(-6) mol/L) on gastrin release. Among all compounds tested, 8-BrcAMP (10(-2) mol/L) was the most potent, stimulating the rate of gastrin release 263% above basal. Both 8-BrcAMP and TPA stimulated gastrin release in a dose-dependent fashion. The biologically inactive phorbol ester, 4 alpha PDD, was without effect at all concentrations. Somatostatin (10(-8) - 10(-6) mol/L) inhibited 8-BrcAMP-stimulated gastrin release in a dose-dependent fashion to a maximum of 75%.
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PMID:Control of gastrin release in cultured gastrinoma-derived G cells. 289 16

We have recently provided evidence from studies conducted in vivo that the ovary, particularly by means of estrogen, regulates placental androstenedione (delta 4A) production during the second half of rat pregnancy. In the present study, an incubation system of dispersed rat placental cells was established to determine if estrogen acts directly on the placenta to regulate delta 4A production. Placentas were obtained on Days 14-15 of rat gestation and dispersed in Hanks' Balanced Salt Solution containing 0.1% collagenase, 0.1% hyaluronidase, 0.01% DNase, and 1% fetal calf serum. Placental cells were incubated in Medium 199 for 16 h at 37 degrees C. A time-dependent increase (r = 0.96, p less than 0.05) in the release of delta 4A occurred over the 16-h incubation period. Mean +/- SE formation of the steroid intermediate progesterone (P4) and product delta 4A was 1.17 +/- 0.78 and 1.18 +/- 0.22 ng per 10(7) cells respectively. The addition of 1-10 microM diethylstilbestrol (DES) decreased (p less than 0.05-0.01) delta 4A production, and had no significant effect on P4 or pregnenolone (P5) formation. The percent decrease in delta 4A production was 14.2 +/- 12.9, 30.9 +/- 2.3, and 55.0 +/- 4.4 with 1, 5, and 10 microM DES, respectively. Treatment of placental cells with estradiol (E2) also resulted in a decrease (p less than 0.01) in delta 4A production with no effect on P4 formation. The percent inhibition of delta 4A production was 34.2 +/- 11.1 and 77.3 +/- 5.2 with the addition of 1 microM and 10 microM E2, respectively. E2 (10 microM) produced a concomitant threefold increase (p less than 0.01) in P5 formation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The effect of estrogen on androstenedione production by rat placental cells in vitro. 292 52

Using monoclonal antibodies, we examined the display of rabbit Ia by articular chondrocytes. We found that 29 to 46% of chondrocytes displayed Ia antigen compared with 46 to 60% of spleen cells. Ia antigen expression was not likely to be the result of enzyme treatment. To investigate antigen presenting activity of enzyme dissociated normal articular chondrocytes, adult rabbits were immunized in the front foot pads with ovalbumin (OVA) in complete Freund's adjuvant. Four to six weeks later, draining popliteal lymph node cells (LNC) were obtained. Articular chondrocytes were obtained by overnight collagenase, DNase, and hyaluronidase digestion of cartilage from both ends of femurs and proximal end of tibias. Antigen-presenting cells from spleen were used as positive controls. LNC and nylon wool-purified T cells were cultured with OVA pulsed and mitomycin C-treated chondrocytes or spleen cells, and lymphocyte proliferation was measured by 3H-TdR uptake. Both chondrocytes and spleen cells showed antigen presenting activity, and stimulation of lymphocyte proliferation was inhibited by murine monoclonal anti-rabbit Ia antibody (2C4), whereas control plasmacytoma cell supernatants had no effect. When T cells were purified first by Sephadex G-10 and later by nylon wool columns, these cells were dependent on antigen-presenting cells for immunogen (OVA)-induced lymphocyte proliferation. Again, chondrocytes under these strict experimental conditions presented antigen to T cells. Chondrocytes also stimulated autologous and allogeneic normal lymphocytes. Thus, normal chondrocytes have Ia antigens on their surface and can function as antigen-presenting cells. These results are significant for the understanding of local cellular interaction in the pathogenesis of rheumatoid arthritis.
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PMID:Class II histocompatibility antigen-mediated immunologic function of normal articular chondrocytes. 293 76


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