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HY Dou JC Wu WL Peng C Chang WK Chi YD Chu CP Hu 《Canadian Metallurgical Quarterly》1998,5(6):428-434
Polyvinyl siloxane impression materials have applications in a variety of indirect procedures in prosthodontics and restorative dentistry. Favourable handling properties, good patient acceptance and excellent physical properties have resulted in their popularity in today's practice. In this review, the chemistry and important physical properties of polyvinyl siloxanes are summarized, and recent clinical questions of improved hydrophilics, tray adhesives, disinfection, and glove-induced polymerization inhibition are addressed. 相似文献
23.
K Talbot I Miguel-Aliaga P Mohaghegh CP Ponting KE Davies 《Canadian Metallurgical Quarterly》1998,7(13):2149-2156
Mutations in the gene encoding the Survival Motor Neuron (SMN) protein are responsible for autosomal recessive proximal spinal muscular atrophy (SMA). SMN orthologues have been identified in the nematode worm Caenorhabditis elegans and the yeast Schizosaccharomyces pombe but, to date, no human paralogues have been described. Here we describe identification and characterization of an SMN-related protein (SMNrp) gene that encodes a novel protein of 239 amino acids, which has recently been identified as a constituent of the spliceosome complex and designated SPF30. Significant similarity to the SMN protein is apparent only within a central region of SMNrp that represents a tudor domain. The SMNrp/SPF30 gene has been mapped to chromosome 10q23. It is differentially expressed, with abundant levels in skeletal muscle. An exclusively nuclear localization for SMNrp in cultured cells and muscle sections was revealed using GFP fusion constructs and thereafter confirmed with a polyclonal antibody raised against SMNrp. Overexpression of SMNrp as a fusion protein in HeLa cells in culture induced dose-dependent apoptosis with positive TUNEL staining. In addition to a possible role for this protein as a pro-apoptotic factor, SMN and its related protein share significant similarities in sequence and cellular function. 相似文献
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SP Goller D Schoisswohl M Baron M Parriche CP Kubicek 《Canadian Metallurgical Quarterly》1998,64(9):3202-3208
Cell extracts of Trichoderma reesei exhibited dibasic endopeptidase activity toward the carboxylic side of KR, RR, and PR sequences. This activity was stimulated by the presence of Ca2+ ions and localized in vesicles of low bouyant density; it therefore exhibited some similarity to yeast Kex2. Analytical chromatofocusing revealed a single peak of activity. The dibasic endopeptidase activity was strongly and irreversibly inhibited in vitro as well as in vivo by 1 mM p-amidinophenylmethylsulfonyl fluoride (pAPMSF) but not by PMSF at concentrations up to 5 mM. We therefore used pAPMSF to study the role of the dibasic endopeptidase in the secretion of protein by T. reesei. Secretion of xylanase I (proprotein processing sequence -R-R- downward arrow-R- downward arrow-A-) and xylanase II (-K-R- downward arrow-Q-) was strongly inhibited by 1 mM pAPMSF, and a larger, unprocessed enzyme form was detected intracellularly under these conditions. Secretion of cellobiohydrolase II (CBH II; -E-R- downward arrow-Q-) was only slightly inhibited by pAPMSF, and no accumulation of unprocessed precursors was detected. In contrast, secretion of CBH I (-R-A- downward arrow-Q-) was stimulated by pAPMSF addition, and a simultaneous decrease in the concentration of intracellular CBH I was detected. Similar experiments were also carried out with a single heterologous protein, ShBLE, the phleomycin-binding protein from Streptoalloteichus hindustanus, fused to a series of model proprotein-processing sequences downstream of the expression signals of the Aspergillus nidulans gpdA promoter. Consistent with the results obtained with homologous proteins, pAPMSF inhibited the secretion of ShBLE with fusions containing dibasic (RK and KR) target sequences, but it even stimulated secretion in fusions to LR, NHA, and EHA target sequences. Addition of 5 mM PMSF, a nonspecific inhibitor of serine protease, nonspecifically inhibited the secretion of heterologous proteins from fusions bearing the NHA and LR targets. These data point to the existence of different endoproteolytic proprotein processing enzymes in T. reesei and demonstrate that dibasic processing is obligatory for the secretion of the proproteins containing this target. 相似文献
26.
CP Karakousis 《Canadian Metallurgical Quarterly》1998,5(6):473-482
BACKGROUND: Therapeutic lymphadenectomies involve the dissection and removal of clinically enlarged, histologically positive nodes at the regional nodal basin, in the absence of detectable distant disease. METHODS: The literature dealing with therapeutic lymphadenectomies in malignant melanoma was reviewed. RESULTS: The rate of wound complications varies with the particular nodal basin. The 5-year survival varies from 19% to 38%, with an average of 26%. Survival is affected primarily by the number of histologically positive nodes and extracapsular spread, and secondarily by the extent of disease at the various levels of the nodal basin, fixation of the nodes, and, probably, the preceding disease-free interval. Prognostic parameters of the primary lesion, e.g., thickness, ulceration, and location, also may have an effect on survival. The rate of local recurrence at the nodal basin after lymphadenectomy has varied from 0.8% to 52%. Adjuvant therapy with interferon alfa-2b has improved the 5-year disease-free survival from 26% to 37%. CONCLUSIONS: Therapeutic node dissections in melanoma provide an appreciable 5-year survival rate, which is further augmented by adjuvant therapy. Many series report a significant rate of local recurrence at the nodal basin following therapeutic dissection. Complete lymphadenectomy reduces the rate of local failure with its attendant morbidity. 相似文献
27.
We report a case of birdshot retinochoroidopathy following a cataract surgery in a 78-year-old man. Low-grade forms of the affection may be discovered lately on a recurrence of the inflammation following any event as an ocular surgical procedure. Medical management of cataract surgery in uveitis is then discussed. 相似文献
28.
Mortality rates and injuries requiring medical treatment associated with sports and exercise are generally low. However, higher injury rates are reported for athletes and members of sports clubs. This study focuses on the sport- and exercise-related injury rate for various age and sex groups in the general population and how sport and exercise injury rates compare with those for other activities. The data presented are based on telephone interviews. Of the participants (N = 6,596), 335 (5.1%) reported having sustained an injury in the previous month; 46% of injuries among males and 14% of those among females were sport or exercise related. The data show a downward trend in sport- and exercise-related injury rates with increasing age. It is concluded that, as a proportion of all injuries sustained, the sport- and exercise-related injury rate is high, particularly among males. Possible future research on sport- and exercise-related injuries is discussed. 相似文献
29.
TP Cotter E O'Shaughnessy S Sheehan B Cryan CP Bredin 《Canadian Metallurgical Quarterly》1996,89(2):62-63
Epidemiological and bacteriological aspects of human Mycobacterium bovis disease were investigated in south-west Ireland (counties Cork & Kerry, population 536,000) over the years 1983-92 inclusive and compared to M. tuberculosis. Results showed a small, stable incidence of culture positive M. bovis human disease, mean annual incidence 0.56 per 100,000 population compared to a higher but declining incidence of culture positive M. tuberculosis (15.3 per 100,000 in 1983, 9.0 per 100,000 in 1992). Male patients were the majority, 63.4 per cent of M. bovis; 62.4% of M. tuberculosis (p = 0.03). Fifty three per cent of M. bovis cases (n = 30) were pulmonary, compared to 85% of M. tuberculosis (n = 626; p = 0.0001). M. bovis patients were older (p = 0.02), mean age 58.4 years (SD 18.9) compared to 48.5 (SD 22.2). The mycobacterial smear positive rate was similar in both groups taken as a whole. No rural-urban difference in incidence was found in either disease, suggesting in the case of M. bovis initial infection in childhood via contaminated milk in the pre-pasteurisation era. 相似文献
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