Indirect detection of anti-acetylcholinesterase compounds in microcolumn liquid chromatography using packed bed reactor with immobilized human red blood cell acetylcholinesterase and choline oxidase

The inhibiting compounds were separated by micro-column liquid chromatography in the mobile phase containing the natural substrate acetylcholine. A home-made packed bed microbioreactor system containing immobilized enzyme acetylcholinesterase (ACHE) in human red blood cell membrane and choline oxidase (CHO) from alcaligenes was used for the post-column conversion of acetylcholine to hydrogen peroxide which was detected by an electrochemical detector. The inhibition effect of the solutes caused a decrease in the acetylcholinesterase activity, a decrease in the formation of hydrogen peroxide and also a decrease in the response corresponding to the concentration of the solutes. The rate of the enzyme regeneration was also recorded. The micro-system was compared with a conventional LC system comprising commercially prepared enzyme reactor. The stability of the enzymes is at least 3 weeks at ambient temperature. The limit of detection depends on biological activity of inhibition and for galanthamine was 1 pmol.     

一种含胆甾醇介晶基团的侧链液晶高分子的合成

以２，４－二异氰酸甲苯酯（２，４—ＴＤＩ）、胆甾醇、丙烯酸β－羟丙酯为原料，合成了含胆甾醇介品基团的侧链液晶高分子、并用ＮＭＲ、ＩＲ和元素分析方法对其结构进行了鉴定。聚合物的相转变温度和形态织构用ＤＳＣ、Ｘ－射线衍射和偏光显微镜进行了测定和观察。     

Pharmacokinetics of intravenously administered sodium dichloroacetate in rabbits

ＰｈａｒｍａｃｏｋｉｎｅｔｉｃｓｏｆｉｎｔｒａｖｅｎｏｕｓｌｙａｄｍｉｎｉｓｔｅｒｅｄｓｏｄｉｕｍｄｉｃｈｌｏｒｏａｃｅｔａｔｅｉｎｒａｂｂｉｔｓＧｕＢｉｎ（顾斌）；ＳｏｎｇＬｉｎｇ（宋岭）；ＪｉａｎｇＹｏｎｇｐｅｉ（蒋永培）；ＷｅｎＡｉｄｏｎｇ（文...     

人体中氧氟沙星的立体选择性代谢

５名健康志愿者日服单剂３００ｍｇ氧氟沙星［（±）－Ｏｆ１］后，采用立体选择性的ＲＰ－ＨＰＬＣ手性流动相添加剂法测定尿中Ｓ－（－）－Ｏｆ１和Ｒ－（＋）－Ｏｆ１浓度结果显示Ｏｆ１在人体内呈现立体选择性代谢。尿中排泄的Ｓ－（－）－Ｏｆ１／Ｒ－（＋）－Ｏｆ１之比随时间变化。服药后２ｈＳ／Ｒ是０．８７５，２４ｈ增加到１．１５０．Ｓ－（－）－Ｏｆ１的消除半衰期（ｔ１／２）是４．５７ｈ；消除速率常数（ｋ）是０．１５４ｈ；药时曲线下的面积（ＡＵＣ）为１．１７ｍｇ·ｈ－１．ｍＬ－１；Ｒ－（＋）－Ｏｆ１的ｔ１／２为４．１８ｈ，ｋ为０．１６８ｈ－１，ＡＵＣ是１．７８ｍｇ·ｈ－１·ｍＬ－１；经配对ｔ检验这三对参数间有显著性差异，Ｐ值分别小于０．０１，０．００１和０．００５．因此两对映体在人体内呈现立体选择性处置     

The relationship of proliferating cell density at the invasive tumour front with prognostic and risk factors in human oral squamous cell carcinoma

BACKGROUND: We hypothesise that the density of proliferating cells at the invasive tumour front (ITF) has a positive relationship with prognostic and risk factors in human oral squamous cell carcinoma (SCC). METHODS: Tissues from 47 human oral SCC specimens were collected and stained with a monoclonal antibody directed against the Ki-67 antigen using a horseradish peroxidase based two-step immunostaining method. Counting was performed on two parallel sections at the ITF using an image analyser. The Ki-67 labelling index (LI) was determined by measuring the number of nuclei/mm(2) of epithelium. RESULTS: Our results show that the density of proliferating cells is related to clinical staging, with advanced stage of disease having a significantly higher Ki-67 LI compared with early stage of disease (2111 +/- 905 vs. 1908 +/- 913; P = 0.03). Importantly, this study shows that tumours that have metastasised have a significantly higher Ki-67 LI than tumours where distant metastasis was not detected (3257 +/- 650 vs. 1966 +/- 881; P < 0.0001). CONCLUSIONS: Cell proliferation, as measured by the Ki-67 LI at the ITF, has a positive relationship with clinical staging, tumour thickness, smoking status of the patient and alcohol consumption. Further, we suggest that a multicenter study with a large cohort of patients is indicated to fully elucidate whether cell proliferation at the ITF is directly related to patient survival.     

Relative frequency of solitary melanocytic lesions of the oral mucosa

Background: Solitary pigmented lesions of melanocytic origin are uncommon in the oral mucosa. These lesions include the oral and labial melanotic macule, oral melanocytic nevus, oral melanoacanthoma, oral melanoma and atypical melanocytic proliferation. The purpose of the study was twofold: to report a large series of solitary melanocytic lesions from one source, and to determine the relative frequency of these lesions. Methods: The study was based on a systematic search of the files of the Pacific Oral and Maxillofacial Pathology Laboratory, University of the Pacific, San Francisco for solitary pigmented melanocytic lesions (benign and malignant) accessed during the years 1984–2002. Results: Of the 89 430 biopsies accessed during the 19‐year period, 773 (0.83%) cases of solitary pigmented melanocytic lesions in the oral mucosa were identified. Oral and labial melanotic macules were the most common melanocytic lesions comprising 86.1% of the entire group and 0.7% of the total number of accessed biopsies. The vermilion border and gingiva were the most common sites (31.1% and 31.0% respectively). Oral melanocytic nevi comprised 11.8% of the entire melanocytic group and 0.1% of the total number of biopsies. The most common site was the palate (44%). Intramucosal nevi were the most common (64%), followed by compound nevi (16.5%) and common blue nevi (16.5%). Junctional nevi were uncommon (3.0%). Oral melanoacanthoma comprised only 0.9% of the entire melanocytic group and 0.008% of the total number of biopsies. Oral melanoma and atypical melanocytic proliferation were the least common lesions each comprising 0.6% of the entire melanocytic group and 0.006% of the total number of biopsies. The most common site for oral melanoma was the palate (60%). Conclusion: The palate was the most common location for both melanocytic nevi and oral melanoma. Thus, all melanocytic lesions in the palate should be viewed with caution and biopsy is recommended to rule out melanoma. Further studies are required to elucidate the entity of oral atypical melanocytic proliferation.     

Development of an open case-based decision-support system for diagnosis in oral pathology

BACKGROUND: Making diagnoses in oral pathology are often difficult and confusing in dental practice, especially for the less-experienced dental student. One of the most promising areas in bioinformatics is computer-aided diagnosis, where a computer system is capable of imitating human reasoning ability and provides diagnoses with an accuracy approaching that of expert professionals. This type of system could be an alternative tool for assisting dental students to overcome the difficulties of the oral pathology learning process. This could allow students to define variables and information, important to improving the decision-making performance. However, no current open data management system has been integrated with an artificial intelligence system in a user-friendly environment. Such a system could also be used as an education tool to help students perform diagnoses. The aim of the present study was to develop and test an open case-based decision-support system. METHODS: An open decision-support system based on Bayes' theorem connected to a relational database was developed using the C++ programming language. The software was tested in the computerisation of a surgical pathology service and in simulating the diagnosis of 43 known cases of oral bone disease. The simulation was performed after the system was initially filled with data from 401 cases of oral bone disease. RESULTS: The system allowed the authors to construct and to manage a pathology database, and to simulate diagnoses using the variables from the database. CONCLUSION: Combining a relational database and an open decision-support system in the same user-friendly environment proved effective in simulating diagnoses based on information from an updated database.     

THE PHARMACOLOGICAL ROLE OF P-GLYCOPROTEIN IN THE INTESTINAL EPITHELIUM

P-glycoprotein, a membrane-associated transport protein, has recently been recognised as an important element of the intestinal epithelium. This paper summarises thein vivodata on the pharmacological role of intestinal P-glycoprotein. These data show that P-glycoprotein contributes to the elimination of many drugs by mediating their direct secretion from the blood into the intestinal lumen. In addition, there is also evidence that this protein can limit oral drug absorption. Hence, inhibition of intestinal P-glycoprotein, e.g. by a reversal agent like cyclosporin A, may be a promising strategy for improving the oral bioavailability of P-glycoprotein substrate drugs. Indeed, several preclinical and clinical studies have shown that coadministration of drugs with a reversal agent can substantially increase oral drug absorption.     

导向喷动流化床生物质快速裂解制液体燃料

在冷模试验得到的优化的结构参数基础上，建立了一套生物质最大处理量为5kg／h的导向管喷动流化床生物质裂解反应器。反应在常压和440～520℃进行，以木屑为生物质原料，二氧化碳和氮气为喷动气或流化气，沙子为流化介质。结果表明该喷动流化床反应器可用于生物质的快速裂解。在400～480℃，液体产率随温度增加而上升，高于480℃时，二次反应的加剧又导致液体产品产率下降。固体和气体的产率则随温度的升高而减少。喷动气和流化气流量的增加均强化了反应器内的传热，并使生物质初始裂解产物的停留时间减少，二次反应进行程度减弱。在适当的裂解条件下液体产率可达73．2％，此时气体和焦的产率分别为12．8％和14．0％。所得液体产品为单一相液体，含水约30％，可用于燃烧。与流化床相比，喷动流化床作为生物质快速裂解反应器可明显提高液体产率。