强的松龙.葡聚糖连接物在大鼠胃肠道内容物中的水解

观察强的松龙．葡聚糖连接物的结肠定向释放特性。方法通过将所合成的强的松龙．葡聚糖连接珠与大鼠胃肠道不同部位内容物稀释液一起孵育,观察强的松龙的释放情况。结果在１６０ｍｉｎ的卵育过程中,强的松龙．葡聚糖连接物的在胃肠道上部内容物中水解释放出少量强的松龙及强的椴龙琥珀酸半酯,最在释放量小于３μｍｏｌ．Ｌ＾－１;而在胃肠道下部内容物中水解释放出大量强的松龙及强的松龙琥珀酸半酯最大释放量为１４μｍｏｌ．Ｌ     

结肠癌免疫相关 lncRNA 风险预测模型的建立

目的 分析影响结肠癌预后的免疫相关 lncRNA, 并构建预测结肠癌患者预后的相关预测模型。 方法 下载 TCGA 数据库中的结肠癌 lncRNA 表达谱, 数据经 TPM 标准化后分析所有 lncRNA 的差异性表 达, 其中缺失值的补充采用 KNN 法, 通过共表达方法提取并鉴定免疫相关 lncRNA, 然后对差异性表达的 lncRNA 进行 LASSO 回归分析, 再进行单因素和多因素 COX 回归分析。 最后使用 R 4. 0. 2 统计学软件的 ggplot2 包基于 lncRNA 风险评分与基因表达关系, 构建风险因子关联图、 KM 曲线及评价模型预测价值的 ROC 曲线。 结果 经过表达差异性分析发现, 共有 2 258 个 lncRNA 在癌和癌旁组织中差异性表达, 其中上 调的有 1 648 个, 下调的有 610 个。 选取差异表达前 100 位的免疫相关 lncRNA 进行 LASSO 回归分析, 共筛 选出 12 个 lncRNA, 再进行单因素和多因素 COX 回归分析后显示 AC092723. 1、 AC007182. 1 和 AC004947. 1 与预后明显相关, 使用 R 4. 0. 2 统计学软件构建预后风险因子关联图, ROC 曲线显示其预测 1 年、 3 年和 5 年的预测价值均较高, 其 AUC 分别为 0. 79 (95 % CI: 0. 67 ~ 0. 91), 0. 78 (95 % CI: 0. 66 ~ 0. 9), 0. 7 (95 % CI: 0. 51 ~ 0. 9)。 结论 研究使用 TCGA 公共数据库进行生物信息学分析并构建的预后模型显示有 较高的预测价值, 除具有一定的临床意义外, 对未来 lncRNA 相关结肠癌的研究也提供了一定的方向。     

Plant foods and colon cancer: an assessment of specific foods and their related nutrients (United States)

Plant foods have been associated inversely with colon cancer. Since amajor focus of this study was to identify components of plant foods whichmay account for their association with colon cancer, nutrients which arecommonly found in plant foods also were evaluated. A population-basedcase-control study was conducted in Northern California, Utah, and the TwinCities area of Minnesota (United States). Complete data were available frominterviewer-administered questionnaires on 1,993 cases and 2,410 controls.Higher intakes of vegetables (for highest relative to lowest quintile ofintake) were associated inversely with colon cancer risk: the odds ratio(OR) was 0.7 for both men (95 percent [CI] confidence interval = 0.5-0.9)and women (CI = 0.5-1.0). Associations were stronger among those withproximal tumors. Total fruit intake was not associated with colon cancerrisk although, among men, higher levels of whole grain intake wereassociated with a decreased risk (OR = 0.6, CI = 0.4-0.9 for older men);high intakes of refined grains were associated with an increased risk (OR =1.5, CI = 1.1-2.1). Dietary fiber intake was associated with a decreasedrisk of colon cancer: OR = 0.5 (CI = 0.3-0.9) for older men; OR = 0.7 (CI =0.4-1.2) for older women; OR = 0.6 (CI = 0.4-1.0) for men with proximaltumors; OR = 0.5 (CI = 0.3-0.9) for women with proximal tumors. Othernutrients, for which plant foods were the major contributor - such asvitamin B6, thiamin, and niacin (women only) - also were associatedinversely with colon cancer. Neither beta-carotene nor vitamin C wasprotective for colon cancer. Adjustment of plant foods for nutrients foundin plant foods or for supplement use did not appreciably alter the observedassociations between plant foods and colon cancer.     

Potent induction of human colon cancer cell uptake of chemotherapeutic drugs by N-myristoylated protein kinase C-α (PKC-α) pseudosubstrate peptides through a P-glycoprotein-independent mechanism

Phorbol ester protein kinase C (PKC) activators and PKC isozyme over-expression have been shown to significantly reduce intracellular accumulation of chemotherapeutic drugs, in association with the induction of multidrug resistance (MDR) in drug-sensitive cancer cells and enhancement of drug resistance in MDR cancer cells. These observations constitute solid evidence that PKC plays a significant role in the MDR phenotype of cancer cells. PKC-catalyzed phosphorylation of the drug-efflux pump P-glycoprotein was recently ruled out as a contributing factor in MDR. At present, the sole drug transport-related event that has been identified as a component of the role of PKC in MDR is PKC-induced expression of the P-glycoprotein-encoding gene mdr1. The objective of this study was to test the hypothesis that PKC can modulate the uptake of chemotherapeutic drugs in cancer cells independently of P-glycoprotein. We analyzed the effects of selective PKC activators/inhibitors on the uptake of radiolabelled cytotoxic drugs by cultured human colon cancer cells that lacked P-glycoprotein activity and did not express the drug efflux pump at the level of message (mdr1) or protein. We found that the selective PKC activator 12-O-tetradecanoylphorbol-13-acetate (TPA) significantly reduced uptake of [¹⁴C] Adriamycin and [³H] vincristine in human colon cancer cells devoid of P-glycoprotein activity, and that PKC-inhibitory N-myristoylated PKC- pseudosubstrate synthetic peptides potently and selectively induced uptake of the cytotoxic drugs in the phorbol ester-treated and non-treated colon cancer cells. TPA treatment of the cells did not induce expression of either P-glycoprotein or its message mdr1. In contrast with [¹⁴C]Adriamycin and [³H] vincristine uptake, [³H] 5-fluorouracil uptake by the cells was unaffected by TPA and reduced by the PKC-inhibitory peptides. These results indicate that PKC activation can significantly reduce the uptake of multiple cytotoxic drugs by cancer cells independently of P-glycoprotein, and that N-myristoylated PKC- pseudosubstrate peptides potently and selectively induce uptake of multiple cytotoxic drugs in cultured human colon cancer cells by a novel mechanism that does not involve P-glycoprotein and may involve PKC isozyme inhibition. Thus, N-myristoylated PKC- pseudosubstrate peptides may offer a basis for the development of agents that reverse intrinsic drug resistance in human colon cancer.     

Effects of prostaglandin F2α(PGF2α) and prostaglandin I2 (PGI2) on nerve-mediated secretion in guinea-pig colon

We have applied conventional flux-chamber and intracellular recording methods to investigate the effects of the prostaglandins PGF₂ and PGI₂ upon epithelial ion transport and on the electrical behaviour of submucosal neurones in guinea-pig colon. In flux-chamber experiments on segments of colon, both prostaglandins evoked a dose-dependent increase in short-circuit current that was reduced in chloridedepleted Krebs solution and by serosal addition of tetrodotoxin or atropine, but was unaffected by hexamethonium. These results indicate activation of chloride secretion via submucosal neurones. The response to PGF₂ was decreased by piroxicam. Application of PGF₂ or PGI₂ to submucosal neurones evoked depolarization of the membrane potential associated with an enhanced spike discharge. The depolarizing response was tetrodotoxin insensitive, indicating a direct effect of the prostaglandins on the impaled neurones. Membrane depolarization was frequently associated with the occurrence of fast excitatory postsynaptic potentials, suggesting in addition that part of the excitatory effect is mediated by the activation of neural circuits that drive the impaled neurone synaptically. The results of this study indicate that the secretory effects of prostaglandins are mediated in part by submucosal neurones and further suggest that the colonic submucosal plexus may function as an amplifier to enhance the epithelial response to inflammatory mediators.     

一期切除吻合术在左半结肠急性梗阻中的应用(附33例报告)

目的：探讨左半结肠急性梗阻如何安全实施一期切除吻合术。方法：回顾分析左半结肠急性梗阻行一期切除吻合术３３例。结果：一期愈合３１例,吻合口瘘１例,死亡率１例。结论：左半结肠急性梗阻只要正确掌握一期切除吻合术适应症,以及完善术中术后处理,可以安全施行一期切除吻合术。     

Primary malignant fibrous histiocytoma of the ascending colon: Report of a case

We report herein an unusual case of primary malignant fibrous histiocytoma (MFH) of the ascending colon. A 47-year-old man was admitted to our hospital for further investigations following the discovery of a mass in the right lower quadrant of the abdomen during a medical checkup. Abdominal ultrasonography (US) and computed tomography (CT) demonstrated a mass extending to the right lateral side from the ascending colon. At laparotomy, a tumor was found originating in the ascending colon and infiltrating the right lateral peritoneum. A right hemicolectomy and partial peritoneal dissection were performed followed by an ileotransverse colostomy reconstruction. The resected specimen contained a tumor measuring 7×5×4 cm, the cut surface of which was yellowish white, and the mucosa of the colon was intact. Based on histological and immunohistochemical inspection, the tumor was diagnosed as MFH of the ascending colon. We reviewed the total 18 known cases of colorectal MFH documented in the literature including our case. After surgery, 4 of 17 patients died of local recurrence, all within 42 months, indicating that early and complete excision of tumor is essential to achieve cure.     

Mediastinal lymph node metastasis of colon cancer: Report of a case

We herein describe a patient with mediastinal lymph node metastases which occurred after both a primary sigmoid colon cancer and metachronous ovarian metastasis had been resected. The most likely route of metastases to the mediastinum in this case is the paravertebral venous plexus probably connected to the ovarian metastasis, or so-called remetastasis. This case illustrates that the mediastinum is thus a possible metastatic site in patients with colon cancer. Surgeons should therefore pay attention to the mediastinum as well as the lung fields when checking chest X-ray films during a follow-up of patients after a resection of colon cancer.     

A new approach to the study of ocular chromatic aberrations

We measured the ocular wavefront aberration at six different visible wavelengths (between 450 and 650 nm) in three subjects, using a spatially resolved refractometer. In this technique, the angular deviation of light rays entering the pupil at different locations is measured with respect to a target viewed through a centered pupil. Fits of the data at each wavelength to Zernike polynomials were used to estimate the change of defocus with wavelength (longitudinal chromatic aberration, LCA) and the wavelength-dependence of the ocular aberrations. Measured LCA was in good agreement with the literature. In most cases the wavefront aberration increased slightly with wavelength. The angular deviations from the reference stimulus measured using a magenta filter allowed us to estimate the achromatic axis and both optical and perceived transverse chromatic aberration (TCA), (including the effect of aberrations and Stiles-Crawford effect). The amount of TCA varied markedly across subjects, and between eyes of the same subject. Finally, we used the results from these experiments to compute the image quality of the eye in polychromatic light.     

Friday,December 8, 1995 8Th Annual San Antonio flow cytometry forum

Summary Pseudomonas exotoxin has been genetically modified so that it targets cancer cells. This was accomplished by deleting its cell binding domain and replacing it with Fv fragments of antibodies that react with breast, colon, and other cancers. Several recombinant immunotoxins are now in clinical trials.Presented at the symposium "New Approaches in the Therapy of Breast Cancer", Georgetown University Medical Center, Washington DC, October 1994, generously supported by an education grant from Bristol-Myers Squibb.