Extended resection, comprising extended right hemicolectomy, splenectomy, and distal pancreatectomy, has been advocated for
carcinoma of the splenic flexure because the lymphatic drainage at this site is variable. The present study addresses the
problems associated with selecting the most appropriate operative procedure to achieve cure of splenic flexure cancers. We
conducted a retrospective review of 27 patients with splenic flexure cancer who under-went curative resection. Left partial
colectomy was performed in 20 patients and partial resection of the transverse/descending colon was performed in 7 patients.
The combined resection of adjacent organs due to tumor adherence was performed in three patients. The spleen and distal pancreas
were the organs most frequently resected among a collective total of six adjacent organs. The median duration of follow-up
was 60.9 months after resection for splenic flexure cancer. No patient developed local recurrence. There was no significant
difference in 5-year survival between patients with splenic flexure cancers and those with colon cancers at other sites. In
conclusion, splenic flexure cancer resected by left partial colectomy or partial resection of the transverse/descending colon
without routine extended resection was not associated with a worse prognosis than colon cancers at other sites.
Received: February 17, 2000 / Accepted: September 26, 2000 相似文献
Short-chain fatty acids (SCFAs) alter ileal and colonic motility, but their effects on duodenojejunal motility are unknown. Simultaneous jejunal manometric recordings and hydrogen breath tests after lactulose were performed in eight healthy subjects during continuous duodenal infusion of either saline or SCFAs. These experiments were conducted in the fasting state and postprandially. The effects of various boluses of SCFAs on duodenojejunal motility were also determined in six subjects. During the fasting period, the number and characteristics of migrating motor complex, prolonged propagated contractions, discrete clustered contractions, motility indes, and orocecal transit time were similar during saline and SCFAs. Similarly, the motility index and the duration of the postprandial period were not different between SCFAs and saline after the meal. The motility index was significantly increased after each of the 100-ml boluses (saline or SCFAs), but was not altered after the 12.5-ml boluses, suggesting a volume-related effect. Thus, SCFAs do not seem to affect proximal small bowel motility in healthy humans.This work was supported in part by a research grant from Institut National de la Santé et de la Recherche Médicale (INSERM) (CRE 887009), and by Smith Kline and French (Paris, France). 相似文献
ObjectivesThe present investigation evaluated the step stress accelerated test (SSALT) load profiles on the survival probability of a glass ceramic under two surface conditions (polished or roughened).MethodsSuprinity–ZLS blocks (Vita Zhanfabrik) were shaped into cylinders, cut in a sawing machine, and crystalized according to the manufacturer's instructions. 60 discs were obtained (Ø = 12 mm, thickness = 1.2 mm) and randomly assigned into two surface conditions: “p” polished surface (400–1200-grit SiC papers), and “r” roughened surface (200-grit SiC papers). Profilometry was performed in all discs to evaluate average surface roughness prior to flexural fatigue strength testing. 3 discs of each group were submitted to biaxial flexural strength in an universal testing machine (0.5 mm/min) and the mean load to failure (N) was calculated to determine SSALT profiles. 27 specimens per surface condition were assigned into three profiles – Mild (n = 9), Moderate (n = 9), and Aggressive (n = 9), and submitted to the fatigue test (60–320 N, 140,000 cycles at 1.4 Hz). The results were analyzed using the Kaplan-Meier and Wilcoxon tests (5%), 2-way ANOVA and Tukey test (α = 5%).ResultsKaplan-Meier and generalized Wilcoxon showed (P = 0.002) that polished groups showed higher survival probability than roughened condition (P < 0.05). A rough internal surface impacted deleteriously on the fatigue strength and reliability of ZLS ceramic. Both surface conditions were more sensitive to the aggressive profile than the other profiles, even worst for the roughened group. Regardless the load profile, 0% survival probability was observed at 384 MPa for polished condition. While for roughened, aggressive tested specimens did not survived 147 MPa followed by moderate at 312 MPa and mild at 384 MPa. The failure modes showed fracture marks originating from superficial grooves for both surface conditions.SignificancePolished specimens are sensitive to the load profile variation, confirming the effect of surface morphology on the fatigue results. 相似文献
ObjectivesThe rapidly increasing use of zirconia-based CAD/CAM multi-layer structures in dentistry calls for a thorough evaluation of their mechanical integrity. This work examines the effect of the multi-layering architecture as well as variations in composition and inclusion of pigments among the layers on the flexural strength of multi-layer zirconias.MethodsA modified 4-point bending test, aided by a Finite Element Analysis (FEA), was used to probe the interfacial strength of 3 classes of yttria-partially-stabilized zirconia: Ultra Translucent Multi-Layer (UTML—5Y-PSZ), Super Translucent Multi-Layer (STML—4Y-PSZ), Multi-Layer (ML—3Y-PSZ). In accord with the size limitation (22-mm height) of CAD/CAM pucks, test samples were prepared in the form of “long” (25 × 2 × 3 mm) and “short” (17.8 × 1.5 × 2 mm) beams. Homogeneous beams (both long and short) were produced from either the Enamel (the lightest shade) or Dentin (the darkest shade) layer, whereas multi-layer beams (short beam only) were obtained by cutting the pucks along their thickness direction, where the material components of various shades were stacked.ResultsThe Enamel and Dentin layers exhibited similar flexural strength for a given material class, with ML amassing the highest strength (800–900 MPa) followed by STML (560–650 MPa) and UTML (470–500 MPa). The 3 classes of multi-layer zirconia showed a trade-off between strength and translucency, reflecting different yttria contents in these materials. The failure stress of the cross-sectional multi-layer beams was, however, ∼30% lower than that of their Enamel or Dentin layer counterparts, regardless of material tested.SignificanceThe weakness of interfaces is a drawback in these materials. Additionally, when measuring strength using short beam flexure, friction between the specimen and supporting pins and accuracy in determining loading span distances may lead to major errors. 相似文献
Objectives. To investigate the reliability of bi-axial flexure and three-point flexure testing of an experimental, low-shrink oxirane-based dental composite, EXL596 compared with two conventional methacrylate based restoratives, Z250 and Z100.
Methods. Specimens (n=20) of a novel oxirane-based composite and two commercially available methacrylate based composites were fabricated for flexural testing to evaluate mean bi-axial flexure strengths, three-point flexure strengths and the associated Weibull moduli (m) following 24 h immersion in a lightproof waterbath maintained at 37±1 °C.
Results. Mean bi-axial flexure strengths and the associated m of EXL596, Z250 and Z100 were 168±11 MPa (m=16.2±4), 140±12 MPa (m=11.9±3) and 126±13 MPa (m=10.2±2), respectively. Three-point flexure strengths and the associated m of EXL596, Z250 and Z100 were 113±15 MPa (m=9.2±2), 92±10 MPa (m=8.5±2) and 79±16 MPa (m=6.3±1), respectively.
Conclusions. The present investigation suggests that bi-axial flexure strength testing of dental resin-based composites provides a more reliable testing method than three-point flexure. The increased reliability was considered in terms of the associated Weibull moduli following bi-axial flexure testing as a result of the elimination of the additional induced variability introduced during the curing regime of three-point flexure specimens. 相似文献