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21.
C Fabris D Basso L Benini T Meggiato G Del Favero G Cavallini M P Panozzo P Fogar C Angonese I Vantini 《Enzyme》1989,42(2):80-86
Serum and urine elastase 1, its renal output and clearance and urinary gamma-glutamyltransferase and ribonuclease excretions were measured in 16 patients with pancreatic cancer, 23 with chronic pancreatitis and in 22 healthy controls in order to evaluate elastase 1 plasma-urine transfer in chronic pancreatic disease and to investigate any factors that might influence the clearance of this enzyme. In an additional group of 17 patients with different pancreatic diseases the serum molecular size distribution of elastase 1 after chromatography was ascertained. An increased urinary elastase 1 output was found in 4/16 patients with pancreatic cancer and in 6/23 with chronic pancreatitis. No correlation was found between circulating elastase 1 and its urinary output; a negative correlation was detected between the serum levels of this enzyme and its clearance. The excretion of ribonuclease and gamma-glutamyltransferase was correlated with elastase 1 output and clearance. While the majority of elastase 1 in serum was accounted for by high molecular forms, probably the expression of complexes with serum inhibitors, free circulating enzyme was present in all patients with high serum elastase 1. Our findings suggest that elastase 1 urinary excretion increases in some patients with chronic pancreatic disease regardless of the neoplastic or inflammatory nature of the illness. Although the availability of different amounts of ultrafiltrable enzyme may play a role in influencing elastase 1 plasma-urine transfer, renal tubular damage appears to be the most important factor influencing the increase in the urinary output of elastase 1. 相似文献
22.
A Del Corso D Barsacchi M Camici D Garland U Mura 《Archives of biochemistry and biophysics》1989,270(2):604-610
Two structurally different forms of bovine lens aldose reductase have been identified. Freshly prepared lens extracts contain an unactivated "b form" (ARb) which is sensitive to inhibition by Sorbinil. Upon incubation of the extracts with oxygen radical generating systems, ARb is converted to a more active "a form" (ARa), which is not inhibited by Sorbinil. ARa and ARb were purified to electrophoretic homogeneity. 相似文献
23.
Expression of bovine and mouse endothelial cell antioxidant enzymes following TNF-alpha exposure 总被引:1,自引:0,他引:1
Endothelial cells are primary targets for injury by reactive oxygen species. Endothelial catalase, copper-zinc superoxide dismutase (CuZnSOD), and manganous superoxide dismutase (MnSOD) provide potential antioxidant enzymatic defenses against oxidant-induced cellular damage. Previous studies in vivo and in vitro have demonstrated that in certain cell types exposure to oxidants may increase the expression of one or more of these antioxidant enzymes, thus providing greater intracellular potential to withstand oxidant-induced cell stress. To test whether endothelial antioxidant enzyme expression is influenced by similar oxidant-induced stresses in vitro, we have exposed endothelial cells to tumor necrosis factor-alpha (TNF-alpha) and have measured levels of catalase, CuZnSOD and MnSOD mRNA, and protein. Our results demonstrate a selective increase of MnSOD mRNA, with coordinate increases of both MnSOD protein and enzyme activity in endothelial cells treated for 24/h with TNF-alpha. In contrast, levels of catalase and CuZnSOD mRNA and protein remained unchanged in these cells after TNF-alpha treatment. These observations were made in microvessel endothelial cells derived from murine and bovine sources. Our results indicate that TNF-alpha can act specifically to increase enzymatic antioxidant potential in endothelial cells by induction of a particular antioxidant enzyme encoding mRNA species. These data demonstrate the capacity of endothelial cells to mount an antioxidant defense in response to exposure to an inducer of oxidative damage. 相似文献
24.
Developmental regulation of expression of the lactate dehydrogenase (LDH) multigene family during mouse spermatogenesis 总被引:4,自引:0,他引:4
K Thomas J Del Mazo P Eversole A Bellvé Y Hiraoka S S Li M Simon 《Development (Cambridge, England)》1990,109(2):483-493
Expression of the Lactate Dehydrogenase (LDH) genes during various stages of spermatogenesis was studied by using a combination of Northern blot analyses and in situ hybridization techniques. These studies have indicated that developmentally programmed expression of all three functional LDH genes occurs during differentiation of germ cells. The LDH/C (ldh-3) gene was expressed exclusively during meiosis and spermiogenesis, beginning in leptotene/zygotene spermatocytes and continuing through to the elongated spermatids. LDH/C (ldh-3) gene expression was accompanied by transient expression of the LDH/A (ldh-1) gene in pachytene spermatocytes and round spermatids. The LDH/B (ldh-2) gene was expressed mainly in Sertoli and spermatogonial cells. By using somatic cell hybrids, the LDH/C (ldh-3) gene has been mapped to mouse chromosome 7, establishing that it is syntenic with the LDH/A (ldh-1) gene locus. Experimental observations made in this study provide new insight into the order and sequence of events involved in the regulation of gene expression of the LDH gene family during spermatogenesis. 相似文献
25.
Elvira D'Alessandro Corinna De Matteis Vaccarella Maria Luisa Lo Re Francesco Cappa Angela D'Alfonso Stefania Discepoli Maria Rosa Della Penna Giuseppe Del Porto 《Human genetics》1988,80(2):203-204
Summary Pericentric inversion of chromosome 19 has been found in several members of three unrelated families from a restricted geographical region. In one of the families, an additional pericentric inversion of chromosome 9 was observed. Reproductive problems, multiple abortions in two families and a neonatal death in the third, were present. A review of previously described cases is included, and the genetic risk connected with this type of rearrangement is also discussed. 相似文献
26.
The genotoxic activity of atrazine, a widely used triazine herbicide, was assayed by the DNA alkaline elution technique in rats given orally a single high dose or repeated daily doses. DNA breaks (and/or alkali-labile lesions) were detected in cell suspensions obtained from stomach, kidney and liver, but not in those from lung. 相似文献
27.
Almond plants (Amygdalus communis L.) of the Garrigues variety were grown in the field drip irrigated and rainfed. Leaf water potential (Ψ) and leaf conductance
(g1) were determined throughout one growing season. Pre-dawn measurement for Ψ in the irrigated treatment was consistent through
the growing season, whereas in the rainfed treatment it decreased gradually. Ψ values at midday (Ψ minimum) was closely dependent
on atmospheric evaporative demand, and their recovery was quicker in the wet treatment than in the dry. The g1 values were higher in the wet than dry treatments, decreasing in both cases by leaf ageing. Maximum values for g1 were reached when evaporative demand was highest in the day. The relationship between Ψ and g1 revealed a decrease in the hysteresis throughout the growing season, being most marked in the dry treatment. The results
highlight the close dependence of Ψ and g1 on evaporative demand, leaf ageing and irrigtion treatment during the growing season. 相似文献
28.
First evidence for polyamine conjugation mediated by an enzymic activity in plants 总被引:3,自引:2,他引:1
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An enzyme activity, found for the first time in plants, mainly located in the 22,000g supernatant of the crude extract of sprout apices of Helianthus tuberosus L. cv OB1 tubers, is able in vitro to covalently bind polyamines to endogenous substrates of different molecular weights. The major assay parameters, such as pH, dithiothreitol, and extract concentrations were optimized. The time course of the reaction, the dependence on putrescine concentration, its competition with histamine, the capacity to bind spermidine and spermine better than putrescine, the stability of the reaction product and analysis of the latter by sodium dodecyl sulfate polyacrylamide gel electrophoresis and thin-layer chromatography suggest that putrescine is linked to endogenous substrates by means of an enzyme reaction that shows some similarities with transglutaminase activities detected in animals. However, the activities of the crude extract and of a fraction eluted from a Sephadex G25 column were not affected by CaCl2 concentrations lower or equal to 5 millimolar; 4 or 10 millimolar EGTA caused a very small reduction; higher concentrations of CaCl2 and 15 millimolar or more of EDTA were inhibitory. N,N′-dimethylcasein was not recognized as a substrate. These data indicate that this activity also displays some characteristics which are different from those of animal transglutaminases. 相似文献
29.
Abstract. The potential of different methods to investigate proliferative activity of cell populations was analysed for non-Hodgkin's lymphomas. Cells in S phase and all cycling cells were determined on cell suspensions obtained from fresh lymph node material by [3 H]-thymidine autoradiography ([3 H]TdR LI), a monoclonal antibody to bromodeoxyuridine (BrdU LI), and the monoclonal antibody Ki67. A good correlation was observed between the values of [3 H]TdR LI and BrdU LI ( r s = 0.90; P < 0.01), [3 H]TdR LI and S phase ( r s = 0.62; P < 0.01) and [3 H]TdR LI and Ki67 ( r s = 0.64; P < 0.01) in individual lymphomas. Using the median values obtained from the different approaches as cut-off points to define slowly and rapidly proliferating tumours, the best agreement was observed between [3 H]TdR LI and BrdU LI (91%) and poorer agreements, even though statistically significant, were observed between [3 H]TdR LI and S phase (73%) or Ki67 (76%). In conclusion, the kinetic information derived from different approaches was more or less concordant and newly proposed approaches should be directly and carefully verified for their prognostic relevance before using them as alternatives to conventional methods. 相似文献
30.
P. Bruzzi E. Negri C. La Vecchia A. Decarli D. Palli F. Parazzini M. R. Del Turco 《BMJ (Clinical research ed.)》1988,297(6656):1096-1098
To determine whether there is a short term increase in the risk of breast cancer after a full term birth data from two hospital based, case-control studies in Italy were pooled. Analysis was restricted to women aged under 50 with two or more children (573 women with cancer and 570 controls). A relative risk for breast cancer of 2.66 was seen in women who had given birth during the three years preceding the interview compared with women whose last birth had occurred 10 or more years before, after adjustment for age, age at first birth, and parity. The relative risk slowly decreased for women who had last given birth three to 10 years before. Multivariate analyses confirmed the protective effect of an early age at first birth and the age dependent effect of parity on the risk of breast cancer--that is, a direct relation below age 40 and an inverse one in older women. These data provide epidemiological evidence that a full term birth is followed by a transient increase in the risk of breast cancer, which for some time contrasts with and overcomes the long term protection of pregnancy at an early age. They therefore confirm predictions from animal studies and theoretical models that pregnancy prevents the early stages of breast carcinogenesis but promotes the late stages of the process. 相似文献