Insulin-like growth factor I activates the invasion suppressor function of E-cadherin in MCF-7 human mammary carcinoma cells in vitro

The calcium-dependent cell-cell adhesion molecule E-cadherin has been shown to counteract invasion of epithelial neoplastic cells. Using three monoclonal antibodies, we have demonstrated the presence of E-cadherin at the surface of human MCF-7/6 mammary carcinoma cells by indirect immunofluorescence coupled to flow cytometry and by immunocytochemistry. Nevertheless, MCF-7/6 cells failed to aggregate in a medium containing 1.25 mM CaCl2, and they were invasive after confrontation with embryonic chick heart fragments in organ culture. Treatment of MCF-7/6 cells with 0.5 microgram ml-1 insulin-like growth factor I (IGF-I) led to homotypic aggregation within 5 to 10 min and inhibited invasion in vitro during at least 8 days. The effect of IGF-I on cellular aggregation was insensitive to cycloheximide. However, monoclonal antibodies that interfered with the function of either the IGF-I receptor (alpha IR3) or E-cadherin (HECD-1, MB2) blocked the effect of IGF-I on aggregation. The effects of IGF-I on aggregation and on invasion could be mimicked by 1 microgram ml-1 insulin, but not by 0.5 microgram ml-1 IGF-II. The insulin effects were presumably not mediated by the IGF-I receptor, since they could not be blocked by an antibody against this receptor (alpha IR3). Our results indicate that IGF-I activates the invasion suppressor role of E-cadherin in MCF-7/6 cells.     

辽宁省城镇居民生活用水定额

本文分析了城镇居民生活用水的特点,介绍了辽宁省城镇居民生活用水定额制定的原则、方法。通过对全省县级以上城镇居民生活用水情况的调查,制定适合辽宁省实际情况的城镇居民生活用水定额。     

影响钢铁工业主要环境因素及其控制措施

针对钢铁工业的环境因素的影响 ,采取针对性措施控制 ,合理利用 ,清洁生产。     

Surgery for primary hyperparathyroidism 1962-1996: indications and outcomes

Twenty-two cases of ameloblastoma and ten cases of adenomatoid odontogenic tumour (AOT) were analyzed comparatively by the AgNOR technique. Ameloblastomas were distributed into three groups according to their clinical behaviour: primary lesions without recurrences (PLWTR), 5 cases; primary lesions with recurrences (PLWR), 4 cases; and recurrences, 13 cases. The cases were also regrouped according to their histological pattern: follicular (9 cases), plexiform (7 cases), acanthomatous (4 cases) and unicystic (2 cases). Considering histological patterns, there was a significant statistical difference only between follicular and plexiform types. There were no significant differences between the group of ameloblastomas and the group of AOTs or between the three groups of ameloblastomas with different clinical behaviour. Our results strongly suggest that the distinct clinical behaviour of ameloblastomas and AOT is not correlated with their cellular proliferation ratio. Thus, the infiltrative ability of the ameloblastomas is probably not related to the cellular proliferation index of these tumours.     

Improved alcohol-fixed smears of fine-needle aspirates for cytology of breast and other palpable lesions

The application of fine-needle aspiration cytology for the diagnosis of solid lesions is well-established. Its sensitivity as a diagnostic tool for both benign and malignant lesions can vary significantly, however, and depends on the quality of the smears submitted. In particular, air-drying artifact can render wet alcohol-fixed smears unsatisfactory for diagnosis. This study examines the basic cause of air-drying artifacts, which is directly related to the moisture of the aspirate that varies among tissues and specimens from any tumor type. A simple modification to the standard smearing technique incorporating precoated slides that introduces moisture into the aspirate is recommended. The technique is applicable to aspirates from all sites without compromising accepted diagnostic cytologic criteria, and offers excellent cytologic clarity with routine stains as well as being flexible enough for other investigative staining methods.     

Arthroplasty implant biomaterial particle associated macrophages differentiate into lacunar bone resorbing cells

OBJECTIVE: To study the pathogenesis of aseptic loosening: in particular, to determine whether macrophages responding to particles of biomaterials commonly used in arthroplasty surgery for arthritis are capable of differentiating into osteoclastic bone resorbing cells, and the cellular and hormonal conditions required for this to occur. METHODS: Biomaterial particles (polymethylmethacrylate, high density polyethylene, titanium, chromium-cobalt, stainless steel) were implanted subcutaneously into mice. Macrophages were isolated from the foreign body granulomas that resulted, cultured on bone slices and coverslips, and assessed for both cytochemical and functional evidence of osteoclast differentiation. RESULTS: Tartrate resistant acid phosphatase (TRAP) negative macrophages isolated from granulomas containing particles of all types of biomaterial composition were capable of differentiating into TRAP positive cells capable of extensive lacunar bone resorption (assessed by scanning electron microscopy). The presence of both UMR106 rat osteoblast-like cells and 1,25-dihydroxy vitamin D3 was necessary for this to occur. CONCLUSION: All implant materials produce wear particles that are the focus of a heavy foreign body macrophage response in the fibrous membrane between a loose implant component and the host bone undergoing resorption. These findings underline the importance of biomaterial wear particle generation and the macrophage response to different types of biomaterial wear particles in the pathogenesis of aseptic loosening.     

The use of interference currents and iodobromine baths in the therapy of patients with chronic nonobstructive pyelonephritis

30 patients were exposed to interference currents (IC) alone (group 1) versus 34 patients treated with IC plus iodobromine baths (group 2). After IC action on the region of the kidney projection patients of group 1 experienced positive changes in cellular and humoral immunity providing an antiinflammatory effect. In group 2, the improvement was seen in renal and urinary functions, 24-h urinary excretion of oxalates and calcium diminished. Interference current proved beneficial in chronic pyelonephritis patients with latent inflammation. The combined therapy was effective in patients at high risk of lithogenesis.     

Gene structure prediction using information on homologous protein sequence

In this paper a new approach for the prediction of protein coding gene structures is described. The principal scheme of prediction is as follows: first, the exons with the best potential are predicted in a sequence with unknown functions and a list of potential amino acid fragments coded by these exons is formed. Second, testing the homology between each amino acid fragment from the list and proteins from the SWISS-PROT database of amino acid sequences. One protein with the best homology is chosen out of all the homologous sequences. Third, reconstruction of the exon-intron structure, basing it on its homology with the chosen protein sequences. The method was tested on an independent control set (20 genes). The results were as follows: 21% of real exons were lost and 3% of non-real exons were found. This system can be used to refine the results of gene prediction systems, especially if highly homologous proteins are found in the amino acid sequence database.