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101.
This study was designed to investigate the effect of retaining coronal tooth substance on the performance of post-retained core materials, and to compare the fracture resistance of the system with an intact tooth prepared to similar dimensions. Ten teeth restored with post-retained silver amalgam, and 10 teeth restored with silver-glass cermet, all with a retained single wall of coronal tooth substance, were compared with 10 unrestored teeth prepared to similar dimensions when subjected to a shearing load. The results showed no statistically significant difference between the unrestored teeth and those restored with a silver-glass cermet. Whilst the teeth restored with silver amalgam had a significantly higher fracture resistance (P > 0.01) there was greater tendency to root fracture. 相似文献
102.
103.
A potential treatment for the amelioration of fetal growth failure is insulin-like growth factor-I (IGF-I). To address concerns of safety and efficacy, IGF-I (80 microg/kg; GroPep Pty.) was administered i.p. to healthy rhesus monkey fetuses via ultrasound guidance every other day between gestational days (GD) 110-120 and 130-140 (third trimester; term = approximately GD 165 +/- 10; n = 6). Pregnancies were monitored sonographically, and fetal/maternal blood samples were collected for complete blood counts, immunophenotyping, and biochemical analyses. Blood samples, external measures of the fetus and newborn, and tissue and organ weights were collected at fetal necropsy (GD 150; n = 2) or at term delivery of neonates (GD 160; n = 4). The results of these investigations have shown no evidence of hypoglycemia in the fetus or dam during the course of treatment. Circulating concentrations of fetal, but not maternal, IGF-I increased with treatment (approximately 80 to approximately 1015 ng/ml), and there was no evidence of a change in serum IGF-II or an increase in IGF binding protein-3 compared with historical control values. Fetal lymphocytes and select red cell parameters increased, and a significant elevation in circulating B cells and CD4/CD8 ratios in fetal lymph nodes was shown. Although no changes were detected in body weights, increases in thymic, splenic, and kidney weights and small intestine lengths occurred. Thus, administration of IGF-I to the fetal monkey is safe and results in 1) transient increases in circulating IGF-I, 2) a significant effect on fetal hematopoietic and lymphoid tissues, and 3) an increase in select fetal organ weights and measures. These data suggest that IGF-I may represent a potential candidate for therapeutic treatment of growth-compromised human fetuses in utero. 相似文献
104.
Cytological identification of soybean mitotic metaphase chromosomes (2n = 40) has been severely limited by their small size and uniform karyomorphology. We have developed fluorescent in situ hybridization (FISH), PCR-primed in situ labelling (PCR-PRINS) procedures, and molecular probes for routine cytological identification and for the physical mapping of soybean somatic chromosomes. Chromosome preparation has been achieved by modifications of previous protocols and through the preparation of root-tip protoplasts prior to chromosome spreading. Initially our probe selection focused on highly repeated DNAs that provide very intense localized hybridization signals. Repetitive gene probes that have proven valuable include the rDNA loci (5S and 45S) which are chromosome specific. We have also developed satellite DNA probes for two different sequence families: the SB92 and the STR120 satellites. Both of these are tandemly arranged at multiple chromosomal loci. By using different cloned examples of each family, we have been able to selectively label unique subsets of soybean chromosomes. Double hybridization with biotin and digoxigenin labeled probes has allowed us to determine the chromosomal overlap between different probes. In addition, we have joined portions of the metaphase chromosome painting patterns with the genetic map by single-copy FISH and PCR-PRINS detection of the RFLP loci G8.15, G17.3, and A199a and A199b. Total genomic DNA in situ hybridization (GISH) patterns were also used to characterize the soybean chromosomes. 相似文献
105.
Between June 1983 and March 1992, we performed a capsular reconstruction procedure through an anterior approach in ten patients (ten shoulders) who had multidirectional laxity of the shoulder and symptomatic atraumatic posterior glenohumeral instability. The procedure included closure of the capsule in the rotator interval and imbrication of the anterior, inferior, and posteroinferior aspects of the capsule by a double-breasting technique that decreases the overall capsular volume. The mean duration of follow-up was sixty months (range, twenty-four to 103 months). According to the system of Rowe and Zarins, the result was graded as excellent for five shoulders, good for four, and poor for one. On the basis of our results, we recommend capsular reconstruction through an anterior approach only in patients who have persistent multidirectional laxity and symptomatic atraumatic posterior instability of the shoulder despite participation in an intensive rehabilitation program. 相似文献
106.
G Fontanini S Vignati D Bigini A Mussi M Lucchi S Chiné CA Angeletti G Bevilacqua 《Canadian Metallurgical Quarterly》1996,2(6):1067-1075
Optimized stent expansion by high-pressure inflations of oversized balloons has initially been derived from experience obtained with the Palmaz-Schatz stent, whereas there is little experience with this strategy in the Wallstent. By using this approach with quantitative coronary angiographic guidance, 20 Wallstents and 20 Palmaz-Schatz stents were implanted in 34 patients and consecutively examined by conventional two-dimensional (2D) intracoronary ultrasound (ICUS) and three-dimensional (3D) ICUS on the basis of the application of a pattern recognition algorithm. Ultrasound criteria of adequate stent expansion were defined as a complete apposition of the stent to the vessel wall, a stent symmetry index (SSI = minimum/maximum lumen diameter) > or = O.7, and a stent-reference lumen area ratio (SRR = Minimum intrastent lumen area/Average of proximal and distal reference lumen area) > or = O.8. In all cases a smooth angiographic lumen and a negative diameter stenosis, on the basis of a distal reference, was achieved. For the Wallstents ICUS showed a higher SSI (2D, 0.95 +/- 0.04 vs 0.85 +/- 0.09; p < 0.001; 3D, 0.90 +/- 0.09 vs 0.82 +/- 0.11, p < 0.05) and a lower SRR (2D, 0.66 +/- 0.12 vs 0.81 +/- 0.13, p < 0.005; 3D, 0.63 +/- 0.14 vs 0.74 +/- 0.15, p < 0.05) than for the Palmaz-Schatz stents. Ninety percent of failure in meeting these criteria resulted from a low SRR. The incidence of incomplete stent apposition (one in both stents) or SSI <0.7 was low and generally associated with an SRR <0.8. The Wallstents met the ICUS criteria less often (2D, 2(1O%) vs 10(50%), p < 0.01; 3D, 3(15%) vs 9(45%), p < 0.05), were significantly longer (35.1 +/- 7.7 mm and 14.3 +/- 3.3 mm, p < 0.0001), and generally demonstrated a larger vessel tapering, measured as proximal minus distal ICUS reference lumen area (1.33 +/- 2.91 mm2 vs 0.44 +/- 1.97 mm(2), not significant). Wallstents meeting the ICUS criteria, however, showed less vessel tapering (0.18 +/- 1.64 mm(2)). Thus optimized stent expansion was followed by excellent angiographic results for both Palmaz-Schatz and Wallstent. Although angiographic results and visual assessment of the ICUS examination suggested a good outcome, few Wallstents met the ICUS criteria in contrast to the Palmaz-Schatz stents. The low value of the SRR in the Wallstents is likely to be caused by vessel tapering, suggesting that this criterion may be unsuitable in assessing the adequacy of the expansion of relatively long stents such as the Wallstent. 相似文献
107.
108.
BF Waller ET Fry TF Peters JB Hermiller CM Orr J VanTassel CA Pinkerton 《Canadian Metallurgical Quarterly》1996,19(11):857-868
While abundant clinical and angiographic data are available regarding features of acute or abrupt closure at the site of balloon angioplasty, little morphologic information is available. This study discusses morphologic-histologic causes for acute closure after angioplasty in 130 necropsy patients. Intimal-medial flaps, elastic recoil, and primary thrombosis were the three leading morphologic causes for closure. Data were subdivided into time categories: abrupt (< 1 day), acute (< 1 week), and early (< 1 month). Intimal-medial flaps remained the most common cause for angioplasty closure despite time from angioplasty to documented occlusion. Morphologic recognition of types and frequencies of angioplasty closure are discussed, and specific mechanical, pharmacologic, or combined treatments are reviewed. 相似文献
109.
Identification of TrkB autophosphorylation sites and evidence that phospholipase C-gamma 1 is a substrate of the TrkB receptor 总被引:1,自引:0,他引:1
The TrkB receptor protein-tyrosine kinase is a receptor for brain-derived neurotrophic factor and neurotrophin-3. In response to brain-derived neurotrophic factor and neurotrophin-3 treatment, TrkB expressed exogenously in Rat-2 cells is rapidly phosphorylated on tyrosine residues. At least 2 regions of TrkB contain phosphorylated tyrosines. The major sites of autophosphorylation are in the region containing Tyr-670, Tyr-674, and Tyr-675, which lies in the kinase domain and corresponds by sequence homology to the Tyr-416 autophosphorylation site in p60c-Src. Tyr-785, which lies just to the COOH-terminal side of the kinase domain in a relatively short tail characteristic of the Trk family of protein-tyrosine kinase receptors, is also phosphorylated in response to neurotrophin-3 treatment. The sequence around Tyr-785 fits a consensus sequence for binding phospholipase C-gamma 1. The simplest interpretation of these results is that, in response to neurotrophin binding, at least two and perhaps all three of the tyrosines in the Tyr-670/674/675 region are autophosphorylated independently, and Tyr-785 is autophosphorylated in vivo. Following activation of TrkB, phospholipase C-gamma 1 is phosphorylated on Tyr-783, Tyr-771, and Tyr-1254. Phospholipase C-gamma 1 also forms a complex with TrkB in response to neurotrophin-3 treatment, consistent with the possibility that one of the TrkB autophosphorylation sites provides a binding site for the phospholipase C-gamma 1 SH2 domains, as is the case for other receptor protein-tyrosine kinases. We conclude that phospholipase C-gamma 1 is directly phosphorylated by TrkB. Since phosphorylation of Tyr-783 and Tyr-1254 results in activation of phospholipase C-gamma 1, we predict that neurotrophin-3 leads to activation of phospholipase C-gamma 1 following binding to TrkB in Rat-2 cells. 相似文献
110.