Perforated colorectal neoplasms: correlation of clinical, contrast enema, and CT examinations

Results of clinical, contrast enema (CE), and computed tomographic (CT) examinations in 39 patients with perforated colorectal neoplasms were retrospectively reviewed. Twenty patients were toxemic at initial presentation, but in only four patients was the diagnosis of perforated colorectal neoplasm initially suspected clinically. CE study was performed in 22 patients and enabled the diagnosis of perforated neoplasm in 11 cases, neoplasm alone in eight, and neither neoplasm nor perforation in three. CT was performed in 38 patients and enabled the diagnosis of perforated neoplasm in 36; pericolic phlegmon but no mass lesion was evident in two. In 16 patients, CT also demonstrated metastatic disease. Because of its reliability in establishing the diagnosis and staging the extent of the inflammatory and neoplastic disease, CT is indicated in cases of suspected or proved perforated colorectal neoplasm and in cases in which CE study findings are indeterminate or suggestive of perforated neoplasm.     

氯仿重结晶棉酚的质量研究

报道了氯仿重结晶的棉酚的化学性质,样品在不同温度下干燥恒重后,经熔点、薄层层析、紫外光谱、红外光谱、X-射线衍射、热重量分析、元素(C,H,Cl)分析及棉酚合量测定等一系列的分析,确证了在60℃以下棉酚与氯仿成溶剂化物(solvate)。随着干燥温度的升高或在室温长时间的贮存,此现象逐渐消失,100℃真空干燥恒重后成为纯棉酚。     

Coralline hydroxyapatite bone graft substitutes: preliminary report of radiographic evaluation

A new bone graft substitute made by conversion of the calcium carbonate exoskeleton of reef-building sea coral into hydroxyapatite has recently become clinically available. The normal radiographic appearance of two forms of this material is described. In the immediate postoperative period, the exoskeletal architecture of these implants is readily appreciated. With graft incorporation over the ensuing months, their intrinsic structure is gradually lost in association with poor marginal definition. Evolving radiographic findings reflect the biocompatible nature of these implants, which provides the potential for ingrowth of native bone with preservation of the coralline scaffold, resulting in enhanced biomechanical properties.     

Staff and student perceptions of a student health service

Results of a survey at one English university suggest that, of the various student personnel services provided by that institution, the Student Health Service was the best known and most used by the students. Both students and academic staff attributed greater importance to that particular service than to any other. Ways in which these two groups of university members justified such special provision are presented and discussed.     

Effect of resin hydrophilicity and water storage on resin strength

This study evaluated the change in the ultimate tensile strength (UTS) of five polymerised resin blends of increasing hydrophilicity, after ageing in distilled water or silicon oil. Resin blocks were prepared from each resin blend by dispensing the uncured resin into a flexible, embedding mould, containing multiple cavities. The resins were polymerised in the moulds under nitrogen at 551.6 kPa and light-activated at 125 degrees C for 10 min. After dry ageing for 24 h at 37 degrees C, the middle third of each resin specimen was trimmed into an 'I' shape. Fifteen control specimens were randomly selected from each resin blend for baseline UTS evaluation. The UTS of the experimental specimens were determined after 1, 3, 6 and 12 months of ageing in water or oil. The UTS of each group of resins at different storage periods in water or oil were analysed using the Friedman multiple ANOVA on ranks and Dunn's multiple comparison tests at 95% confidence level. Significant reduction (p < 0.01) in UTS was observed in Groups II-V resins after 12-month storage in water, while the most hydrophobic Group I resin showed no significant change (p > 0.05) in the same period. The percentage reduction in UTS increased with the hydrophilicity of the resin blends. Long-term water storage of hydrophilic resin blends such as those employed in dentine adhesives, resulted in a marked reduction in their mechanical strength that may compromise the durability of resin-dentine bonds.     

Defects in neurofibromatosis 2 protein function can arise at multiple levels

Neurofibromatosis 2 (NF2) is an inherited cancer syndrome resulting from mutations in the NF2 tumor suppressor gene. Analysis of NF2 mutations has revealed some general genotype-phenotype correlations. Severe disease has been associated with mutations that produce a premature termination while more mild disease has been associated with missense mutations. Here, we provide experimental proof for these genotype-phenotype correlations by demonstrating that nonsense mutations fail to produce stable merlin protein while missense mutations result in the generation of merlin proteins defective in negative growth regulation. This inability to suppress cell growth may result from defects in the function of merlin at several levels, including failure to form an intramolecular complex. Based on these findings, we propose a model for merlin growth suppression that provides a framework for analyzing NF2 patient mutations and merlin function.