Effects of endotoxin on intestinal hemodynamics, glutamine metabolism, and function

The purpose of this study was to investigate the intestinal hemodynamics and gut glutamine metabolism during endotoxemia, and their correlation with altered intestinal absorptive capacity and permeability. Seventeen Sprague-Dawley rats were used in the study. The endotoxin group (ENDO) recieved endotoxin (10 mg/kg intraperitoneally,n=9), while the control group (CONT,n=8) received saline injection. Twelve hours later, D-xylose (0.5 g/kg) and fluorescein isothiocyanate-dextran (FITC-dextran, 750 mg/kg) were given by oral gavage. One hour later abdominal aortic (AA) blood flow, superior mesenteric venous (SMV) flow, mean arterial pressure (MAP), central venous pressure (CVP), and SMV pressure (SMVP) were also measured. The MAP, AA, and SMV blood flow decreased (P<0.05), while the CVP and SMVP increased (P<0.05) in the ENDO group as compared with the CONT group. The ENDO group showed significant decreases for both intestinal glutaminase activity and net intestinal glutamine uptake (P<0.05). The D-xylose concentration in SMV decreased significantly (P<0.05) in the ENDO group as compared with the CONT group. However, the plasma FITC-dextran concentration showed no significant difference between the groups. Endotoxin produced a hypodynamic effect in rats 12h after intraperitoneal administration in association with both a decreased intestinal glutamine metabolism and an absorptive capacity.     

Relationship between phenotypes of cell-function differentiation and pathobiological behavior of gastric carcinomas

AIM To reveal the correlation between thefunctional differentiation phenotypes of gastriccarcinoma cells and the invasion and metastasisby a new way of cell-function classification.METHODS Surgically resected specimens of361 gastric carcinomas (GC) were investigatedwith enzyme-, mucin-, and tumor-related markerimmunohistochemistry. According to thedirection of cell-function differentiation,stomach carcinomas were divided into fivefunctionally differentiated types.RESULTS ① Absorptive function different-iation type (AFDT): there were 82 (22.7%)patients including 76 (92.7%) aged 45 years.Sixty-nine (84.1%) cases belonged to theintestinal type. Thirty-eight (46.3%) expressedCD44v6 and 9 (13.6%) of 66 male patientsdeveloped liver metastasis. The 5-year survivalrate of patients in this group (58.5%) was higherthan those with the other types (P<0.01). ②Mucin secreting function differentiation type(MSFDT): 54 (15%) cases. Fifty-three (98.1%)tumors had penetrated the serosa, 12 (22.2%)expressed ER and 22 (40.7%) expressedCD44v6. The postoperative 5-year survival ratewas 28.6%. ③ Absorptive and mucin-producingfunction differentiation type (AMPFDT): there were 180 (49.9%) cases, including 31 (17.2%)aged yanger than 45 years. The tumor was morecommon in women (62, 34.4%,) and expressedmore frequently estrogen receptors (ER) (129,81.7%) than other types (P<0.01). Ovarymetastasis was found in 12 (19.4%) out of 62female subjects. The patients with this type GChad the lowest 5-year survival rate (24.7%)among all types. ① Specific functiondifferentiation type (SFDT) : 13 (3.6%) cases.Nine (69.2%) tumors of this type derived fromAPUD system, the other 4 (30.7%) were ofdifferent histological differentiation. Sixty percent of the patients survived at least five years.⑤ Non-function differentiation type (NFDT): 32(8.9%) cases. Nineteen (59.4%) cases hadlymph node metastases but no one with liver orovary metastasis. The 5-year survival rate was28.1%.CONCLUSION This new cell-functionclassification of GC is helpful in indicating thecharacteristics of invasion and metastasis of GCwith different cell-function differentiationphenotypes, Further study is needed to disclosethe correlation between the cell-functionaldifferentiation phenotypes and the relevantgenotypes and the biological behavior of gastriccarcinoma.     

Safety and accuracy in the clinical recording of cerebrospinal fluid pressure

Summary A pressure transducer with a disposable, presterilized fluid chamber was developed to increase the safety margin when recording cerebrospinal fluid (CSF) pressure. With this system the fluid compartment is completely separated from the transducer proper, reducing electrical hazard and the risk of infection. The operational range is form — 20 mm Hg to 300 mm Hg with good static accuracy. The transducer with stopcocks has a flat frequency response of up to 75 Hz, showing that the two-part principle is compatible with good dynamic performance.The transducer system was easy to handle and well suited to the recording of ventricular fluid pressure, detection of spinal subarachnoid block, the investigation of CSF absorptive capacity, as well as blood pressure recording. When the transducer was connected to standard disposable stopcocks, needles, and tubing as for these recordings, the dynamic accuracy of the whole apparatus was satisfactory for analysis of the pulsatile wave-form. A total of 185 CSF pressure recordings was performed without complication.     

不同血液净化方法对慢性肾衰竭维持性血液透析患者血清β2-微球蛋白的影响

目的 探讨不同血液净化方法对慢性肾衰竭维持性血液透析(MHD)患者血清β2-微球蛋白(β2-MG)的清除效果.方法 将40例慢性肾衰竭MHD患者随机分为四组:血液透析(HD)组,高通量血液透析(HFD)组,血液透析滤过(HDF)组,HD+血液吸附(AP)组,每组各10例.记录患者治疗前后血清β2-MG测得值并进行组内和组间统计学比较.结果 HD组第1次血液净化后β2-MG测得值[(53.49±1.15)mg/L]较第1次血液净化前(基线值)[(49.10±2.31)ms/L]上升但差异无统计学意义(P>0.05),6个月血液净化后β2-MG测得值[(55.63±1.30)mg/L]较基线值上升且差异有统计学意义(P<0.05).HFD组、HDF组和HD+AP组第1次血液净化后及6个月血液净化后β2-MG测得值较基线值均有明显下降趋势(P<0.05).并且HD+AP组6个月血液净化后β2-MG测得值较HFD组和HDF组下降趋势更为明显(P<0.05).结论 HD对β2-MG无清除效果,HFD、HDF和HD+AP能有效清除β2-MG,并且6个月后HD+AP清除β2-MG效果更佳.     

白藜芦醇衍生物(BTM-0512)在大鼠体肠吸收特性研究

目的:研究白藜芦醇衍生物[(E)-3,5,4′-三甲氧基-1,2-二苯乙烯(BTM-0512)]在大鼠肠道的吸收特性。方法:采用大鼠在体肠循环实验,考察不同的药物浓度、肠段及胆汁对吸收参数的影响。BTM-0512在大鼠肠循环液中的药物浓度采用HPLC法测定;循环液中酚红浓度采用UV法测定。结果:在肠道正常PH值情况下,低、中、高3个浓度的BTM-0512的吸收速率常数(K_a)分别为0.6290、0.5329(扎胆管)、0.5330(未扎胆管)、0.6791h~(-1),表明不同浓度BTM-0512在肠道的吸收速率常数相近,且胆汁对BTM-05 12肠道吸收没有影响(P>0.05);在十二指肠、空肠、回肠、结肠的吸收速率常数分别为0.9492、0.5216、0.3835、0.1185 h~(-1),统计结果显示,不同肠段间吸收有明显差异(P<0.05)。结论:BTM-0512在肠道内是以被动扩散的方式被吸收,呈现一级动力学过程。因BTM-0512在整肠段均有吸收,剂型设计时可考虑肠溶制剂。     

豚鼠小肠诱发电位的实验研究

本研究利用豚鼠测定禁食时间不同和不同部位小肠对葡萄糖、乳糖、甘氨酸，亮氨酸吸收的诱发电位最大值（ＰＤｍａｘ）及最大半饱和浓度（ＣＫ）。结果表明：空肠，回肠对葡萄糖，乳糖的吸收一致，对氨基酸的吸收，回肠的功能高于空肠，诱发电位均值与小肠吸收功能一致。提示，测定诱发电位可以定性定量地观察小肠对糖类及氨基酸的吸收情况。     

Intestinal Absorption of (–)-Carbovir in the Rat

(–)-Carbovir (CBV) is a carbocyclic nucleoside analogue with in vitro activity against the human immunodeficiency virus. The sites and mechanism of absorption of (–)-CBV from the rat small intestine were studied in the anesthetized male Sprague–Dawley rat. (–)-CBV was perfused through either duodenal, jejunal, or ileal segments at three concentration levels ranging from 1 to 500 µg/mL. The fraction remaining to be absorbed at steady-state and the absorptive clearance were calculated for each experiment. The effect of solvent drag on the absorptive clearance was also investigated. Two-way ANOVA for the absorptive clearance per unit length was not significant for either (–)-CBV concentration or site of perfusion. The fraction remaining to be absorbed at steady-state was found to be 0.804 ± 0.091 (n = 30). A strong correlation was found between the absorptive clearance and the net water absorptive flux. The mechanism of (–)-CBV absorption across the rat small intestine apparently consists of both passive diffusion and convection.     

复方碳酸钙泡腾颗粒剂处方筛选及溶出度考察

目的对复方碳酸钙颗粒剂的处方组成进行筛选,并考察制剂中钙元素累积溶出度。方法以颗粒剂干燥失重(%)为指标,均匀试验设计法筛选出复方碳酸钙颗粒剂处方中乳糖、山梨醇、PVP等辅料用量。以钙尔奇D为对照,原子吸收分光光度法测定钙离子浓度,转篮法比较了2种药物中钙元素在不同生理盐水和稀盐酸液中的累积溶出度。结果碳酸钙泡腾颗粒剂的最佳处方组成为乳糖∶PVP∶山梨醇=70∶5∶10;颗粒剂与钙尔奇D片在生理盐水中的钙累积溶出参数T     

长三角地区外商直接投资的技术外溢与吸收效果——基于长江三角洲16个城市的面板数据分析

在长三角经济增长中,外商直接投资（FDI）起到了显著的推动作用,FDI的溢出效应是存在的。长江三角洲基础设施和科学事业经费的投入能够提高对FDI溢出效应的吸收能力,而人力资本投入对FDI溢出效应的吸收能力作用并不显著。基础设施形成的吸收效果仍然存在边际递增效应,而科学事业经费的投入的吸收效果存在边际递减效应。进一步提高外商直接投资的质量,加快长江三角洲先进制造业基地的建设,大力引进外资研发机构是今后长江三角洲地区利用外资的重点。     

金丝桃苷在Caco-2细胞模型中的跨膜转运方式

目的研究金丝桃苷在Caco-2细胞模型中的吸收机制。方法用Caco-2细胞单层模型研究金丝桃苷的双向转运,考察pn、药物质量浓度、方向、温度、抑制剂对金丝桃苷细胞转运的影响。采用HPLC法检测金丝桃苷的含量,计算其表观渗透系数(P_app)。结果金丝桃苷的细胞转运P_app。具有pH依赖性。金丝桃苷肠腔（A）侧→基底（B）侧P_app>B→A,并且随着金丝桃苷质量浓度的增大而减小,具有浓度依赖性。P-gp抑制剂维拉帕米增加金丝桃苷的细胞正向转运P_app,降低了其逆向转运P_app。金丝桃苷较高浓度时,MRPl抑制剂吲哚美辛和ATP抑制剂叠氮化钠显著降低了金丝桃苷的转运量。结论金丝桃苷在Caco-2细胞单层模型中的转运具有pH依赖性和浓度依赖性,是以主动转运为主,被动扩散为辅,同时涉及外排蛋白作用的转运方式。