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排序方式: 共有6130条查询结果,搜索用时 15 毫秒
1.
The objective of this study was to investigate the absorption behavior of chikusetsusaponin IVa (CHS‐IVa) in the rat intestine using single‐pass intestinal perfusion (SPIP) and to classify CHS‐IVa into the biopharmaceutics classification system (BCS). The equilibrium solubility of CHS‐IVa was determined by the shaker method. The absorption mechanism of CHS‐IVa in the intestine was studied by comparing the Peff of different concentrations of CHS‐IVa. The intestinal site dependence of CHS‐IVa absorption was studied by comparing the Peff of the same concentration of CHS‐IVa in different intestinal segments. The relationship between CHS‐IVa and intestinal efflux protein was studied by perfusion with an efflux protein inhibitor. The permeability of CHS‐IVa was investigated by comparing the Peff of CHS‐IVa and the reported value. The solubility of CHS‐IVa over the pH range 1.0–7.5 was 14.4 ± 0.29 to 16.9 ± 0.34 mg/ml. The Peff of CHS‐IVa in the duodenum was 1.76 × 10?3 to 2.00 × 10?3 cm/min. The Peff of CHS‐IVa in the jejunum was 1.26 × 10?3 to 1.39 × 10?3 cm/min. The Peff of CHS‐IVa in the ileum was 1.25 × 10?3 to 1.31 × 10?3 cm/min. The Peff of CHS‐IVa in the colon was 1.02 × 10?3 to 1.08 × 10?3 cm/min. There was no statistical difference of the Peff in the four segments at different CHS‐IVa concentrations. The Peff of CHS‐IVa (0.07, 0.7 and 7.0 mg/ml) were all notably smaller than the reported Peff (3.00 × 10?3 cm/min) in the jejunum. The Peff of CHS‐IVa was not influenced by verapamil (P‐gp inhibitor), indomethacin (MRP inhibitor) and pantoprazole (BCRP inhibitor). CHS‐IVa was classified as high solubility, low permeability and BCS III. The main absorptive tracts were the upper intestinal tracts and the rank order of intestinal permeability was duodenum > jejunum ≈ ileum > colon. The transport mechanism of CHS‐IVa in all intestinal segments might be primarily passive transport. CHS‐IVa was not a substrate of P‐gp, MRP and BCRP. 相似文献
2.
Anthony Z Faranesh Dara L Kraitchman Elliot R McVeigh 《Magnetic resonance in medicine》2006,55(5):1114-1123
The purpose of this work was to investigate the use of an intravascular contrast agent to determine perfusion kinetics in skeletal muscle. A two-compartment kinetic model was used to represent the flux of contrast agent between the intravascular space and extravascular extracellular space (EES). The relationship between the image signal-to-noise ratio (SNR) and errors in estimating permeability surface area product (Ktrans), interstitial volume (ve), and plasma volume (vp) for linear and nonlinear curve-fitting methods was estimated from Monte Carlo simulations. Similar results were obtained for both methods. For an image SNR of 60, the estimated errors in these parameters were 10%, 22%, and 17%, respectively. In vivo experiments were conducted in rabbits to examine physiological differences between these parameters in the soleus (SOL) and tibialis anterior (TA) muscles in the hind limb. Values for Ktrans were significantly higher in the SOL (3.2+/-0.9 vs. 2.0+/-0.5x10(-3) min-1), as were values for vp (3.4+/-0.8 vs. 2.1+/-0.7%). Differences in ve for the two muscles (8.7+/-2.2 vs. 8.5+/-1.6%) were not found to be significant. These results demonstrate that relevant physiological metrics can be calculated in skeletal muscle using MRI with an intravascular contrast agent. 相似文献
3.
4.
豚鼠耳蜗微血管内皮细胞体外通透性的研究 总被引:1,自引:0,他引:1
目的 研究豚鼠耳蜗微血管内皮细胞的体外通透性特征。方法 在成功建立豚鼠耳蜗微血管内皮细胞体外通透性模型的基础上 ,研究该体外模型跨细胞电阻及对12 5I 牛血清白蛋白的通透性。结果 ①耳蜗微血管内皮细胞在培养增殖过程中其跨细胞电阻呈动态变化过程 ,以 5× 10 4/cm2 的细胞密度接种时 ,7d左右电阻到达峰值 ,其跨细胞电阻峰值大小为 (118 9± 18 5 )Ω/cm2 ;②体外模型中加入12 5I 牛血清白蛋白后 ,其通透性呈上升期抛物线型曲线 ,90min内几乎呈直线。结论 跨细胞电阻及对12 5I 牛血清白蛋白变化曲线能反映体外耳蜗微血管内皮细胞的通透性特征 相似文献
5.
《中国药理学与毒理学杂志》1997,(1)
本实验探讨了内源性速激肽是否参与白三烯C4(LTC4)的气道效应.LTC4(0.5μgkg-1,iv)可增高豚鼠肺内压(IPP)和气道内依文思蓝渗出。速激肽NK-1受体拮抗剂CP-96345{(2S,3S)-顺式-2-(二苯甲基)-N-[(2-甲氧苯)-甲基]-1-杂氮双环[2.2.2]辛烷-3-胺}1mgkg-1,iv,可减弱LTC4诱导的依文思蓝渗出;NK-2受体拮抗剂SR-48968{(S)-N-甲基-N-[4-(4-乙酰氨基-4-苯基哌啶)-2-(3,4-二氯苯基)丁基]苯甲酰胺},1mgkg-1,iv,可抑制IPP的增高.白三烯拮抗剂ONO-1078(0.03mgkg-1,iv)可阻断这两种反应.结果说明内源性速激肽增强LTC4的气道作用,其中NK-1受体介导微血管渗漏,NK-2受体介导支气管收缩. 相似文献
6.
Lucio Lucchin Amleto D’Amicis Maria Gabriella Gentile Nino Carlo Battistini Maria Antonia Fusco Augusta Palmo Maurizio Muscaritoli Franco Contaldo Emanuele Cereda 《Mediterranean journal of nutrition and metabolism》2009,2(3):171-179
Aim and methods Nutrition, unhealthy lifestyles and cancer appear to be strictly related, but few authors have analysed the interest in dietary
information of cancer patients and their families. This survey was conducted in the Veneto area (Italy) to investigate the
concern of cancer patients and their family members about diet as a health tool before and after diagnosis of cancer.
Results Seven hundred and four questionnaires were collected: 380 from cancer patients and 324 from family members of cancer subjects.
Breast cancer (BC) was the most frequent disease for patients (61.8%) as well as families (26.5%). Generally, the importance
of having precise diet information after diagnosis is recognised by 40.3% of patients, with significant differences between
the various types of cancer: gastric and colon/rectum cancer (GCC) patients were more concerned than BC women about precise
information concerning a diet to follow immediately after diagnosis (p = 0.000, ODs = 3.10, CI 1.68–5.71) or during treatments (p = 0.001, ODs = 2.67, CI 1.46–4.89). The nutritional information is supplied to patients in 34% of cases and to relatives
in 30.3%, often from non-medical sources. In total healthcare workers (family doctor, oncologist, surgeon, dietician) represented
the exclusive source of dietary information for 24.9% of patients and 22.9% of family members. Diet after diagnosis changes
in 69.1% of GCC patients and in 39.2% of BC women. Relatives, particularly women, report difficulties preparing patients’
meals in 30.7% of cases, changes in the eating habits of the entire family in 29.9% and discontent connected with patients
diet in 13.9%. The concern about proper nutrition after diagnosis increases more in GCC subjects (p < 0.025) when compared to BC subjects and in patients with more recent diagnosis (p < 0.041) when compared with patients with diagnosis >5 years ago, while in family members the interest in diet after diagnosis
increases more in women than in men (p < 0.030) without other differences regarding the degree of relationship, type of cancer or diagnosis time. Relatives (92.7%)
have more interest in nutritional education than patients (74.9%). Cancer patients <65 years were more interested in educational
initiatives concerning nutrition (p = 0.000, ODs = 4.46, CI 2.6–7.4) than older patients (>65 years) and female subjects were more concerned than male patients
(p = 0.008, ODs = 2.11, CI 1.2–3.6).
Conclusions The interest in the dietary knowledge and in educational initiatives concerning nutrition is high in cancer patients and their
relatives, although it decreases with the age. The poor attention paid to nutrition of cancer patients by various healthcare
workers deserves consideration, since the psychophysical wellbeing and perhaps also survival of cancer patients can be improved
by correct dietary management, as well as, naturally, by the principal treatments themselves. 相似文献
7.
利用过氧化氢的氧化作用参与抗原抗体反应,使细胞的膜通透性增强,利于荧光标记抗体染液渗入,从而更快速、广泛地接触抗原,更有效的抗原抗体的嵌合交联。新技术的应用,增强了染色效果,缩短了实验时间,简化了操作,提高了阳性检出率,使实验准确性提高,为临床确诊、疗效观察及预后提供了可靠依据。 相似文献
8.
目的:探讨改进的内外括约肌在原位肛门整形重建术中的应用及其手术效果。方法:改进包括:①肛门内括约肌改进为双层双环肌套;②肛门外括约肌改进为股薄肌采用“围巾式”环绕结肠末端一周,其远端剖为两条,一条缝合固定于耻骨韧带;另一条缝合固定于骶尾韧带,即为肛门外括约肌重建和外括约肌浅部和深部的重建。结果:38例术后肛门外形及功能和远期生活质量、生存率均更为满意。术后随访总优良率达94.73%;远期生存率达76.32%。结论:低位直肠癌Miles术后,同时行改进的内外括约肌原位肛门整形重建的效果是可行的,更接近正常的肛门解剖结构和生理功能。 相似文献
9.
研究了聚环氧氯丙烷(PECHCH)/N(4-乙氧基苄叉)4-丁基苯胺(EBBA)复合膜对氧气和氮气的透过性和选择性。用示差扫描量热计(DSC)、解偏振光强仪(DLI和偏光显微镜考察了复合膜的形态结构。结果表明,当PECH/EBBA复合膜处于液晶的向列相转变温度时,有较高的气体透过性和选择性。发现只有复合膜中EBBA含量在30wt%以上,PECH和EBBA呈非均相混合时,才有较明显的富氧效果。当EBBA含量达50wt%时,氧氮分离系数α=3.78。 相似文献
10.
Vascular hyperpermeability is a cardinal feature of inflammation or bum in which an array of inflammatory mediators can cause such changes in the microvessels. The fimctional measures of microvascular exchange that represent the properties of microvascular wails are the permeability coefficients which have been reported from measurements on intact whole organisms (including human subjects}, on perfused tissues and organs, on single perfused microvessels, and on monolayers of cultured microvascular endothelial cells. In this review, we summarize some experiments of vascular permeability in individually isolated perfused microvessels. 相似文献