超声内镜检查88例上消化道黏膜下肿物的应用体会

目的　探讨超声内镜对上消化道黏膜下肿物的诊断价值。方法　对普通胃镜疑有黏膜下肿物者 ,即行超声内镜检查。结果　 88例黏膜下肿物中 ,外压征 11例 ,平滑肌瘤 5 4例 ,平滑肌肉瘤 6例 ,静脉瘤 6例 ,脂肪瘤 5例 ,异位胰腺 2例 ,淋巴瘤 1例 ,胃粗大皱襞 3例。其中有 1例平滑肌瘤误诊为平滑肌肉瘤。结论　超声内镜能较为准确地诊断黏膜下肿物 ,但有时对鉴别良恶性肿瘤有一定困难     

小探头超声内镜在上消化道粘膜下肿瘤诊断和治疗中的应用

目的探讨小探头超声内镜在上消化道枯腹下肿瘤诊断和治疗中价值。方法对117例常规内镜诊断为上消化道粘膜下肿瘤的病人，行小探头超声内镜险查，部分小探头超声内镜后行内镜下电切、氩气刀、手术切除等，并分析相关结果。结果117例常规内镜诊断为上消化道粘膜下肿瘤的病人行小探头超声检查诊断为壁外压迫22例（占18．8%），95例为消化管壁病变，其中平滑肌瘤58例（占61．1%），平滑肌肉瘤4例（占4．2％），脂肪瘤5例（占5．3％），异位胰腺6例（占6．3％），息肉12例（占12.6％），粗大粘膜皱襞4例（占4.2%），管壁囊肿3例（占3.2%），孤立静脉瘤3例（占3．2％）。其中32例经过高频电切、手术取得足够病理标本者，病检结果平滑肌瘤12例、平滑肌肉瘤4例、异位胰腺4例、息肉12例。结论小探头超声内镜能准确显示消化道各层结构，对判断壁外压迫和粘膜下肿瘤的起源、大小、性质具有很大的价值。EUS是粘膜下肿瘤进一步治疗方法选择的首批方法．但在判断肿瘤的良恶性仍有一定的局限性。     

透明质酸钠、甘油果糖混合液黏膜下注射行内镜黏膜下剥离术:26例临床分析

背景:内镜黏膜下剥离术(ESD)逐渐成为消化道早期癌症和癌前病变的首选治疗手段,但目前对术中选择何种黏膜下注射液尚未达成共识。目的:评估ESD术中黏膜下注射透明质酸钠、甘油果糖混合液的临床价值。方法:纳入2007年12月～2009年8月扬州市第一人民医院收治的26例经染色内镜和内镜超声检查诊断为消化道黏膜及黏膜下病变的患者,黏膜下注射透明质酸钠、甘油果糖混合液行ESD治疗,分析操作一般情况、剥离成功率以及穿孔发生率。结果:本组患者切除标本最大长径1.3～4.3cm,平均2.6cm;ESD操作时间28～162min,平均62.6min;平均黏膜下注射量为26.6ml。剥离成功率92.3%。1例食管平滑肌瘤术后出现纵隔气肿,经保守治疗后痊愈,穿孔发生率3.8%。ESD术后患者平均住院时间为4.2d,平均随访4.5个月,复查内镜示创面基本愈合,无复发。结论:黏膜下注射透明质酸钠、甘油果糖混合液行ESD的疗效良好,安全性高。     

Dieulafoy病内镜诊治中的几个问题探讨（附22例报告）

目的探讨上消化道粘膜下恒径小动脉破裂出血（Dieulafoy病）的内镜诊断与治疗。方法对2005-04～2008-02胃镜检查诊断的22例Dieulafoy病住院病例进行分析。结果22例患者用HLE液内镜粘膜下注射治疗,1次注射止血有效率77.3%,2次注射止血总有效率86.4%,有3例注射治疗后仍有活动性出血行手术治疗。平均住院天数11.7d。结论对于Dieulafoy引起的上消化道大出血,内镜HLE液粘膜下注射治疗是有效的;诊断上需与消化性溃疡、肿瘤等引起上消化道出血的原因相鉴别。     

Self-recognition and self-selection in multicomponent supramolecular coordination networks on surfaces

Self-recognition, self-selection, and dynamic self-organization are of fundamental importance for the assembly of all supramolecular systems, but molecular-level information is not generally accessible. We present direct examples of these critical steps by using scanning tunneling microscopy to study mixtures of complementary organic ligands on a copper substrate. The ligands coordinate cooperatively with iron atoms to form well ordered arrays of rectangular multicomponent compartments whose size and shape can be deliberately tuned by selecting ligands of desired length from complementary ligand families. We demonstrate explicitly that highly ordered supramolecular arrays can be produced from redundant ligand mixtures by molecular self-recognition and -selection, enabled by efficient error correction and cooperativity, and show an example of failed self-selection due to error tolerance in the ligand mixture, leading to a disordered structure.     

Temperature dependence of protein motions in a thermophilic dihydrofolate reductase and its relationship to catalytic efficiency

We report hydrogen deuterium exchange by mass spectrometry (HDX-MS) as a function of temperature in a thermophilic dihydrofolate reductase from Bacillus stearothermophilus (Bs-DHFR). Protein stability, probed with circular dichroism, established an accessible temperature range of 10 °C to 55 °C for the interrogation of HDX-MS. Although both the rate and extent of HDX are sensitive to temperature, the majority of peptides showed rapid kinetics of exchange, allowing us to focus on plateau values for the maximal extent of exchange at each temperature. Arrhenius plots of the ratio of hydrogens exchanged at 5 h normalized to the number of exchangeable hydrogens vs. 1/T provides an estimate for the apparent enthalpic change of local unfolding, ΔH°_unf(avg). Most regions in the enzyme show ΔH°_unf(avg) ≤ 2.0 kcal/mol, close to the value of kT; by contrast, significantly elevated values for ΔH°_unf(avg) are observed in regions within the core of protein that contain the cofactor and substrate-binding sites. Our technique introduces a new strategy for probing the temperature dependence of local protein unfolding within native proteins. These findings are discussed in the context of the demonstrated role for nuclear tunneling in hydride transfer from NADPH to dihydrofolate, and relate the observed enthalpic changes to two classes of motion, preorganization and reorganization, that have been proposed to control the efficiency of hydrogenic wave function overlap. Our findings suggest that the enthalpic contribution to the heavy atom environmental reorganizations controlling the hydrogenic wave function overlap will be dominated by regions of the protein proximal to the bound cofactor and substrate.     

Elusive transition state of alcohol dehydrogenase unveiled

For several decades the hydride transfer catalyzed by alcohol dehydrogenase has been difficult to understand. Here we add to the large corpus of anomalous and paradoxical data collected for this reaction by measuring a normal (> 1) 2° kinetic isotope effect (KIE) for the reduction of benzaldehyde. Because the relevant equilibrium effect is inverse (< 1), this KIE eludes the traditional interpretation of 2° KIEs. It does, however, enable the development of a comprehensive model for the “tunneling ready state” (TRS) of the reaction that fits into the general scheme of Marcus-like models of hydrogen tunneling. The TRS is the ensemble of states along the intricate reorganization coordinate, where H tunneling between the donor and acceptor occurs (the crossing point in Marcus theory). It is comparable to the effective transition state implied by ensemble-averaged variational transition state theory. Properties of the TRS are approximated as an average of the individual properties of the donor and acceptor states. The model is consistent with experimental findings that previously appeared contradictory; specifically, it resolves the long-standing ambiguity regarding the location of the TRS (aldehyde-like vs. alcohol-like). The new picture of the TRS for this reaction identifies the principal components of the collective reaction coordinate and the average structure of the saddle point along that coordinate.     

Laparoscopic surgery for submucosal tumors located at the esophagogastric junction and the prepylorus

Background  Laparoscopic partial gastric resection is widely accepted as a treatment for gastric submucosal tumors (SMTs). However, SMTs of either end of the stomach are generally managed by subtotal gastrectomies or total gastrectomies. This study was conducted to evaluate surgical techniques for management of SMTs located at the ends of the stomach. Methods  Among 63 patients who were diagnosed and underwent laparoscopic surgery for gastric SMTs at Seoul National University Bundang Hospital from May 2003 to May 2007, 11 SMTs located at the ends of the stomach were identified. The clinicopathologic results of these 11 SMTs were analyzed. Results  Laparoscopic partial wedge resections or tumor excisions were successfully performed on all patients except for those who had prepyloric tumors. Six men and five women had SMTs at the ends of the stomach. The patients ranged in age from 21–63 years (mean 43.4 ± 13.5 years). Of six esophagogastric junctional tumors that showed low, homogeneous contrast enhancement on computed tomography (CT) scans, five were treated by laparoscopic transgastric enucleation and one by tumor-everting resection. One esophagogastric junctional tumor that leaned toward the fundus and showed a 6-cm-diameter endophytic mass with heterogeneous enhancement on CT scan was resected by laparoscopic wedge resection. The mean operation time was 100 min (range 60–210 min). Three laparoscopy-assisted distal gastrectomies and one laparoscopic wedge resection were performed on SMTs located near the prepyloric antrum. There were no intra- or postoperative complications. Duration of postoperative hospital stay ranged from 4–7 days. Conclusion  Laparoscopic local resection is an effective treatment for SMTs located at the esophagogastric junction and can be used instead of a total or proximal gastrectomy. However, gastrectomies should be considered for SMTs located near the pylorus because of the small volume of the lower third of the stomach.     

Histological factors contributing to a high risk of recurrence of submucosal invasive cancer (pT1) of the colon and rectum after endoscopic therapy

We analyzed the histological high-risk factors for recurrence of submucosal invasive carcinomas (pT1) of the colon and rectum after endoscopic therapy, examining pT1 cancers treated primarily by endoscopic resection within a 23-year period. We compared recurrent and nonrecurrent cancers, evaluating the following "highrisk factors" of the primary lesion: massive invasion, a surgical margin <2 mm but negativity for cancer in the cut end, poorly differentiated adenocarcinoma (PD) (G3), undifferentiated carcinoma (G4), and/or positive angiolymphatic invasion. The following histological factors were defined as predictive of a low risk: minimum invasion, a surgical margin >2 mm, well or moderately differentiated adenocarcinoma (G1, G2), and no evidence of angiolymphatic invasion. We analyzed the records of 37 patients with pT1 cancers, including 15 with high-risk factors who underwent subsequent resection. Local recurrence with or without liver metastases developed in 4 of these 15 patients. The histological type was PD in three (75%) of the four recurrent lesions. All four (100%) lesions showed a desmoplastic response (DR). Only 1 (9%) of the 11 patients without recurrence after subsequent surgery had a lesion with a small component of PD, and only three (27%) lesions showed a mild DR. We concluded that endoscopic therapy is inadequate for pT1 cancers with a histological PD component, and/or a DR in the cancer stroma.