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991.
Ornithine decarboxylase from mouse epidermis and epidermal papillomas: differences in enzymatic properties and structure. 总被引:2,自引:1,他引:1
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T G O''''Brien T Madara J A Pyle M Holmes 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(24):9448-9452
The properties of ornithine decarboxylase (OrnDCase) from mouse epidermis and benign epidermal tumors (papillomas) induced by the initiation-promotion protocol were compared. When crude extracts from each tissue were incubated at 55 degrees C, epidermal OrnDCase was rapidly inactivated, but the papilloma OrnDCase was more heat stable. Each of five individual papilloma extracts contained OrnDCase activity that was considerably more resistant to heat inactivation than was epidermal OrnDCase. Mixing of a papilloma and epidermal extract produced an intermediate heat-inactivation profile, suggesting that the differences in OrnDCase heat stability are not due to non-OrnDCase components of the extracts. Kinetic analyses indicated that the papilloma OrnDCase has an altered affinity for its substrate, L-ornithine, compared to epidermal OrnDCase. The apparent Km for L-ornithine for the epidermal enzyme was 0.07 mM while the Km values for the individual papilloma OrnDCases clustered around two higher values, 0.3 mM and 1.0 mM. The papilloma OrnDCases, but not epidermal OrnDCase, were activated by GTP and to a lesser extent by CTP. Immunoblot analysis showed the existence of multiple forms of OrnDCase in both epidermis and papilloma that differed in isoelectric point but not subunit molecular weight. None of the species of OrnDCase present in the epidermal extract coincided with the species present in papilloma. These results suggest that one consequence of neoplastic transformation in this in vivo system is the presence of an OrnDCase protein in benign tumors that differs structurally and functionally from the OrnDCase present in normal epidermis. The possible mechanisms responsible for these results and their significance for neoplastic development in this tissue are discussed. 相似文献
992.
Integration of adeno-associated virus vectors in CD34+ human hematopoietic progenitor cells after transduction 总被引:4,自引:0,他引:4
Gene transfer vectors based on adeno-associated virus (AAV) appear promising because of their high transduction frequencies regardless of cell cycle status and ability to integrate into chromosomal DNA. We tested AAV-mediated gene transfer into a panel of human bone marrow or umbilical cord-derived CD34+ hematopoietic progenitor cells, using vectors encoding several transgenes under the control of viral and cellular promoters. Gene transfer was evaluated by (1) chromosomal integration of vector sequences and (2) analysis of transgene expression. Southern hybridization and fluorescence in situ hybridization analysis of transduced CD34 genomic DNA showed the presence of integrated vector sequences in chromosomal DNA in a portion of transduced cells and showed that integrated vector sequences were replicated along with cellular DNA during mitosis. Transgene expression in transduced CD34 cells in suspension cultures and in myeloid colonies differentiating in vitro from transduced CD34 cells approximated that predicted by the multiplicity of transduction. This was true in CD34 cells from different donors, regardless of the transgene or selective pressure. Comparisons of CD34 cell transduction either before or after cytokine stimulation showed similar gene transfer frequencies. Our findings suggest that AAV transduction of CD34+ hematopoietic progenitor cells is efficient, can lead to stable integration in a population of transduced cells, and may therefore provide the basis for safe and efficient ex vivo gene therapy of the hematopoietic system. 相似文献
993.
Noninfiltrating angiolipoma of the mediastinum 总被引:1,自引:0,他引:1
A case of mediastinal angiolipoma in a 63-year-old man is described. A computed tomographic scan of the thorax demonstrated a large encapsulated mass with fatty and soft-tissue components near the esophagus. This appearance was considered suggestive of a liposarcoma. However, at surgery a benign noninfiltrating angiolipoma was found and removed. To the authors' knowledge, angiolipomas have not previously been reported to occur within the mediastinum. 相似文献
994.
995.
Pseudoaneurysms complicating pancreatitis: detection by CT 总被引:3,自引:0,他引:3
Burke JW; Erickson SJ; Kellum CD; Tegtmeyer CJ; Williamson BR; Hansen MF 《Radiology》1986,161(2):447-450
Complications of pancreatitis such as pseudocyst formation and abscess are well known to radiologists. Secondary formation of pseudoaneurysms has not been emphasized in the radiologic literature. The great morbidity and mortality associated with pseudoaneurysms emphasize the importance of early detection. Three patients are described whose angiographically proved pseudoaneurysms were demonstrated on contrast material-enhanced abdominal CT scans obtained for evaluation of pancreatitis. A homogeneously enhancing structure within or adjacent to a pancreatic pseudocyst or contiguous with a vascular structure should be considered highly suspicious for an associated pseudoaneurysm. 相似文献
996.
997.
Background Diclofenac sodium is a non-steroidal anti-inflammatory agent commonly used to provide analgesia postsurgery. It is common
clinical practice to administer a diclofenac suppository at induction to contribute to pre-emptive analgesia (PEA). Diclofenac
takes up to 30 minutes to attain maximal plasma level after rectal administration.
Aim To compare post-operative analgesia in patients who received diclofenac 30–45 minutes preoperatively, or at induction of
anaesthesia.
Methods A prospective, randomised, double-blind controlled trial in 157 patients undergoing varicose vein surgery. Group A (control)
received a rectal placebo 30–45 minutes preoperatively, group B received diclofenac 100mg 30–45 minutes preoperatively and
group C received placebo 30–45 minutes preoperatively and diclofenac 100mg at induction. Outcome measures were Visual Analogue
Scores (VAS) and requirement for rescue analgesia.
Results Patients in group A had significantly poorer analgesia than patients in groups B and C. There were no significant differences
in VAS values and requirements for rescue analgesia between groups B and C 3–4 hours and 18–22 hours postoperatively.
Conclusion For patients undergoing varicose vein surgery preoperative administration of rectal diclofenac significantly improves post-operative
analgesia and this effect is independent of whether it is given at induction or 30– 45 minutes preoperatively. 相似文献
998.
Renal cell carcinoma: earlier discovery and increased detection 总被引:10,自引:0,他引:10
999.
Kaufmann SJ; Eastaugh JL; Snowden S; Smye SW; Sharma V 《Human reproduction (Oxford, England)》1997,12(7):1454-1457
Infertility affects one in six couples at some time in their lives, with
48% of these couples requiring assisted conception techniques in order to
achieve a pregnancy. Whilst the overall clinical pregnancy rate per embryo
transfer is 23%, this varies widely between clinics. The Human
Fertilisation and Embryology Authority has attempted to analyse the results
of all units, with weighting of different factors affecting assisted
conception, and the published data have invariably led to comparisons
between units. However, statistical models need to be developed to
eliminate bias for valid comparisons. Neural networks offer a novel
approach to pattern recognition. In some instances neural networks can
identify a wider range of associations than other statistical techniques
due in part to their ability to recognize highly non-linear associations.
It was hoped that a neural network approach may be able to predict success
for individual couples about to undergo in-vitro fertilization (IVF)
treatment. A neural network was constructed using the variables of age,
number of eggs recovered, number of embryos transferred and whether there
was embryo freezing. Overall the network managed to achieve an accuracy of
59%.
相似文献
1000.
Orbital tuberculoma masquerading as an orbital malignancy 总被引:1,自引:0,他引:1
Background: Orbital tuberculosis is exceedingly rare in areas where tuberculosis is non-endemic. A case of childhood orbital tuberculosis is reported, which the authors believe to be the first reported case of orbital tuberculosis in the Australasian region. Methods/Results: The patient, a 6-year-old boy, presented with proptosis and was initially mistaken to have an orbital malignancy. Treatment with antituberculous drugs resulted in resolution of the condition. Conclusion: This case served as a timely reminder of the need to keep awareness of the extrapulmonary manifestations of tuberculosis alive even in developed countries. A high index of suspicion for this eminently treatable disease in the appropriate clinical situation is particularly important when migrant communities from high-prevalence areas are involved. 相似文献