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161.
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AA Zargarov II Senin AM Alekseev SV Shul''ga-Morsko? PP Filippov VM Lipkin 《Canadian Metallurgical Quarterly》1996,22(7):483-488
Numerous data strongly suggest the involvement of cytokines and the matrix metalloproteinase collagenase (MMP-1) in the pathogenesis of periodontitis. Recently, we have demonstrated that, upon culturing under the influence of IL-1 alpha + EGF, a large amount of inactive procollagenase (MMP-1) is stored in the extracellular matrix of periosteal tissue. We now show that this endogenous reservoir of proenzyme can be operative after activation with plasmin and is able to induce a rapid and almost complete breakdown of the collagenous extracellular matrix. The level of collagen degradation following activation showed a strong correlation with the amount of proenzyme that was incorporated in the tissue. The highest level of degradation (70% of the total amount of collagenous proteins) was found with the IL-1 alpha + EGF-treated explants, followed by those treated with IL-1 alpha alone (35%). Explants cultured with EGF or in the absence of cytokines, containing only small amounts of procollagenase, showed little collagen breakdown following plasmin activation (7%). Inhibition of metalloproteinases by EDTA, or blockage of plasmin by PMSF, prevented the degradation in all explants irrespective of the amount of proenzyme present in the tissue. Our findings demonstrate that endogenous proenzyme stored in a native connective tissue matrix can be activated at a later time interval which results in a massive breakdown of the tissue. This study shows a possible pathway of collagenase-induced breakdown without recent de novo synthesis of the enzyme. Such a sequence may be operative in chronic inflammatory diseases, such as periodontitis, where production of procollagenase under the influence of cytokines spans a longer time period, whereas breakdown is often characterized by a cyclic behaviour. 相似文献
163.
VH Karsdorp GA Dekker A Bast GJ van Kamp AA Bouman JM van Vugt HP van Geijn 《Canadian Metallurgical Quarterly》1998,80(1):39-44
The topoisomerase II alpha (topo II alpha) enzyme is the target for several chemotherapeutic agents, including etoposide, teniposide, mitoxantrone, and doxorubicin (topo II poisons). The enzyme also is a marker of cell proliferation. Most cases of Hodgkin's disease (HD) are responsive to combination chemotherapy regimes that include topo II poisons such as doxorubicin. Immunoperoxidase methods for detection of the topo II alpha isoenzyme are now available for use in formalin-fixed, paraffin-embedded tissues, which may provide information about the proliferative capacity and possible sensitivity of tumors to drugs that target topo II. We used a specific antibody to analyze subsets of HD for topo II alpha staining patterns. Formalin-fixed blocks from 49 cases of HD, including 20 nodular sclerosis (NS), 14 mixed-cellularity (MC), and 15 lymphocyte-predominant (LP) subtypes, were analyzed by dual staining for topo II in combination with monoclonal antibodies against Reed-Sternberg (RS) cells consisting of CD15 for the NS and MC subtypes and CD20 for LP lymphocytic and histiocytic (L & H) cells. The number of morphologically appropriate cells coexpressing the RS or L & H marker and topo II alpha was quantitated. Positive nuclear staining for topo II alpha in RS or L & H cells was seen in 100% of cases, irrespective of subtype. Coexpression of CD15 and topo II alpha was seen in 58.4% of the RS cells or mononuclear variants in NSHD cases and 68.4% in MCHD cases. No significant difference in the percentage of neoplastic cells expressing topo II alpha was found between NS and MC subtypes. Cases of LPHD showed coexpression of CD20 and topo II alpha in 84.4% of the L & H cells, a significant increase over the level of tumor cell coexpression seen in NSHD and MCHD (P < .001). Only one case was found to have a low (< 25% of tumor cell coexpression) level of topo II alpha expression. Immunohistochemical detection of a high level of topo II alpha expression in HD, irrespective of subtype, suggests a molecular explanation for the excellent response of most HD to standard combination chemotherapy, which can include topo II poisons. The LP subtype has a higher expression of topo II alpha in the neoplastic cell population than do NS or MC subtypes, perhaps indicating increased sensitivity of these tumors to topo II poisons. It may be possible to identify subsets of HD that are more or less sensitive to conventional chemotherapeutic regimes, which would help in the selection of appropriate treatment. 相似文献
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J Müntzing RY Kirdani J Saroff GP Murphy AA Sandberg 《Canadian Metallurgical Quarterly》1977,10(5):439-445
Estracyt (estramustine phosphate) injected intraperitoneally, 100 mg, per Kg. three days a week for four weeks, retarded growth of the R-3327 tumor in intact rats and in orchiectomized rats given androgen. The growth inhibition was accomplished by reduction of tumor deoxyribonucleic acid concentration and of the activities of acid phosphatase, leucine aminopeptidase, and other hydrolases. Histologic examination revealed cellular necrosis particularly prominent in the orchiectomized, androgen-treated rats. Estracyt did not affect the uptake of 65-Zn in the tumors but markedly reduced the high uptake in the dorsolateral prostate. There was no accumulation of 3H or 14C in the tumors after intravenous administration of 3H, 14C-labeled Estracyt, but the isotope concentrations decreased much in the same way as they decreased in the dorsolateral prostate. The isotopes were retained in the ventral prostate, where their concentrations were approximately twenty times higher than those in the muscle four hours after injection. The results demonstrate the value of the R-3327 tumor in the evaluation of drugs of potential clinical use for the treatment of prostatic cancer. The results also show that Estracyt has an antitumor effect which is not dependent on the antigonadotropic action of the drug. 相似文献
166.
AV Nedostup EA Bogdanova EI Mikhnovski? AA Platonova 《Canadian Metallurgical Quarterly》1977,17(4):85-90
The structure of cardiac rhythm was studied with the help of specialized computers during digitalization in 60 patients with atrial fibrillation of different etiology. The reduction of the heart contractions rate under digitalization is accompanied by certain changes in the structure of cardiac rhythm: the arrhythmic pattern of the ventricular contractions increases with a predominant growth of the number of long R--R intervals, the transitions from short intervals to longer ones become sharper, and portions of a relatively stable ventricular rhythm appear. Three main types of dynamics of the rhythm structure were distinguished on the basis of the changes in the interval R--R histogram. The described changes in the structure of cardiac rhythm are not specific, but when Digitalis drugs are used alone they can be used as additional criteria for digitalization. 相似文献
167.
A retrospective analysis of 89 patients who underwent jejunoileal bypass surgery for morbid obesity disclosed 33 complications that were detected radiographically. Intestinal obstruction (10.1% of patients), cholecystitis (5.6%), renal stones (4.5%), peptic ulcer (3.4%), megacolon (6.7%), and elongation of the small intestine with hypertrophy of the mucosal folds of the jejunum (6.7%) were diagnosed solely by radiographic means. 相似文献
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