bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examination of the impact of a range of Pluronic surfactants on the in-vitro solubilisation behaviour and oral bioavailability of lipidic formulations of atovaquone
Authors: Sek Leab , Boyd Ben J , Charman William N , Porter Christopher J H 
Published: May 2006

Abstract
Exogenous surfactants are increasingly used to enhance the dispersion properties of lipid-based formulations of poorly water-soluble drugs, yet their possible effects on formulation digestion and oral bioavailability in-vivo are not well documented. In this study, in-vitro dispersion and digestion experiments were conducted using formulations comprising a blend of long-chain glycerides, ethanol, a model poorly water-soluble drug (atovaquone), and a series of surfactants including Cremophor EL and a range of Pluronic surfactants (Pluronics L121, L61, L72, L43 and F68). Inclusion of Cremophor EL, a surfactant with a high hydrophilic-lipophilic balance (HLB), promoted complete digestion of the formulation and effective dispersion and solubilisation of the lipolytic products and co-administered drug. Surprisingly, formulations containing the Pluronic (L121) with the lowest HLB (0.5) equally effectively promoted digestion and drug solubilisation and a trend towards decreased digestion and drug solubilisation was observed with Pluronics of increasing HLB values. All formulations effectively prevented drug precipitation, suggesting possible utility in-vivo, and no correlation was evident between the ability of the formulations to self-emulsify on dispersion and to promote drug solubilisation on digestion. Subsequent assessment of the oral bioavailability of atovaquone after administration of formulations containing Cremophor EL or Pluronic L121 or a simple solution of atovaquone in long-chain glycerides confirmed the utility of lipid-based formulations for enhancing the oral bioavailability of poorly water-soluble drugs such as atovaquone, but also indicated that in some cases microemulsion preconcentrate formulations may not provide additional bioavail-ability benefits beyond that achievable using simple lipid solutions.
Intestinal permeability and excretion into bile control the arrival of amlodipine into the systemic circulation after oral administration
Authors: Raušl Dragica , Fotaki Nikoletta , Zanoški Ružica , Vertzoni Maria , Cetina-Čižmek Biserka , Khan M Zahirul I , Reppas Christos 
Published: May 2006

Abstract
The objective of this study was to identify the factors controlling the arrival of amlodipine into the systemic circulation after oral administration in the fasting state. Dissolution data were collected with the rotating paddle and the flow-through apparatus. Caco-2 cell lines were used to assess the intestinal permeability characteristics. Actual in-vivo data were collected in 24 fasted healthy subjects after single-dose administration of the same amlodipine besylate tablet formulation used in the in-vitro dissolution studies. Regardless of the hydrodynamics, dissolution of amlodipine besylate tablets was rapid and complete in media simulating the contents of the upper gastrointestinal tract in the fasting state. Permeability of amlodipine through Caco-2 cell lines was lower than propranolol's and higher than ranitidine's, indicating that transport through the intestinal mucosa may be one process that limits the arrival into the systemic circulation. Indeed, the deconvoluted profile indicated that arrival into portal blood occurs at rates much slower than gastric emptying or dissolution rates. However, prediction of amlodipine's mean plasma profile after oral administration became possible only after additionally assuming excretion of amlodipine into the bile and a reasonable gastrointestinal residence time. Interestingly, in-vitro permeability data collected in this or in previous studies were inappropriate for simulating the mean actual plasma profile.
Sesquiterpene lactones from Lychnophora pohlii: neutrophil chemiluminescence inhibition and free radical scavenger activity
Authors: Kanashiro Alexandre , Kabeya Luciana M , Grael Cristiane F F , Jordão Christiane O , Azzolini Ana Elisa C S , Lopes João Luis C , Lucisano-Valim Yara M 
Published: May 2006

Abstract
Excessive production of reactive oxygen species (ROS) by polymorphonuclear leucocytes (PMNLs) is thought to contribute to the pathology of many inflammatory diseases. Sesquiterpene lactones (STLs) seem to be important contributors to the anti-inflammatory activity of many species of Lychnophora (Asteraceae), which have been widely used in Brazilian folk medicine because of this pharmacological property. In this study, the inhibitory effects of three STLs isolated from Lychnophora pohlii (lychnopholide, centratherin and goyazensolide) on rabbit PMNL oxidative burst were evaluated by the luminol-enhanced chemiluminescence (CL-lum) assay. All STLs tested showed concentration-dependent inhibitory activity on CL-lum but were not cytotoxic to PMNLs (evaluated by lactate dehydrogenase release) under the assessed conditions. Moreover, goyazensolide, the most active STL, had no free radical scavenger property, as assessed by 1,1-diphenyl-2-picrylhydrazyl radical assay, and had no inhibitory effect on the luminol-horseradish peroxidase-hydrogen peroxide chemiluminescence. Taken together, the results of this investigation suggest that the concomitant presence of methacrylate ester and hydroxyl groups contributes to a high inhibitory effect on PMNL oxidative metabolism. This effect was not mediated by free radical scavenger or cytotoxic effects, but probably by inhibition of enzymes involved in the signal transduction pathways of the ROS generation process.
Participation of epoxygenase activation in saikogenin D-induced inhibition of prostaglandin E2 synthesis
Authors: Toriniwa Yasufumi , Lv Xiaochuan , Kodama Yasuo , Ohizumi Yasushi , Yoshida Makoto , Nakahata Norimichi 
Published: May 2006

Abstract
We examined the effect of saikogenin D on arachidonic acid metabolism in C6 rat glioma cells to clarify its anti-inflammatory mechanism. Incubation of C6 cells with saikogenin D for 20min resulted in the inhibition of prostaglandin E2 production and the accumulation of an arachidonic acid metabolite that was found to be 11,12-dihydroxyeicosatrienoic acid, a metabolite of 11,12-epoxyei-cosatrienoic acid. C6 cells expressed rat epoxygenase mRNAs, CYP1A1, CYP2B1 and CYP2J3, which converted arachidonic acid to epoxyeicosatrienoic acids. 11,12-Epoxyeicosatrienoic acid inhibited A23187-induced prostaglandin E2 production and SKF-525A, an inhibitor of epoxygenase, attenuated the saikogenin D-induced inhibition of prostaglandin E2 production in C6 cells. Furthermore, 11,12-epoxyeicosatrienoic acid and 11,12-dihydroxyeicosatrienoic acid, but not saikogenin D, inhibited the activity of cyclooxygenase in a cell-free condition. These data suggest that saikogenin D activates epoxygenases that rapidly convert arachidonic acid to epoxyeicosanoids and dihydroxyeicosatrienoic acids, and then the metabolites secondarily inhibit prostaglandin E2 production.
Surfactin C inhibits platelet aggregation
Authors: Kim Sung Dae , Park Sun Kyu , Cho Jae Youl , Park Hwa Jin , Lim Jong Hwan , Yun Hyo In , Park Seung Chun , Lee Kyoung Youl , Kim Sang Keun , Rhee Man Hee 
Published: May 2006

Abstract
This study was designed to investigate the effect of surfactin C, which is derived from Bacillus subtilis, on platelet aggregation and homotypic leucocyte aggregation. Surfactin C strongly and dose-dependently inhibited platelet aggregation, which was stimulated both by thrombin (0.1 U mL−1), a potent agonist that activates the G protein-coupled protease receptor, and by collagen (5 μg mL−1), a potent ligand that activates αIIbβ3 with IC50 values (concentration inhibiting platelet aggregation by 50%) of 10.9 and 17.0 μM, respectively. Moreover, surfactin C significantly suppressed the intracellular Ca2+ mobilization in thrombin-activated platelets. Surfactin C, however, did not affect various integrin-mediated U937 cell aggregation, implying that the anti-platelet activity of surfactin C was not due to its detergent effect but by its action on the downstream signalling pathway. Therefore, the results suggest that surfactin C may have a beneficial therapeutic effect on aberrant platelet aggregation-mediated cardiovascular diseases.
Monodisperse Organosilica Microcapsules with Functional Groups by Self-catalysis
Authors: Fei Bin , Lu Haifeng , Wang Rong Hua , Xin John H 
Published: May 2006

Abstract
On the basis of the self-catalytic sol–gel reaction of methyl trimethoxysilane (MTMS) and 3-aminopropyl trimethoxysilane (ATMS) at oil/water interface, monodisperse organosilica microcapsules with functional groups were prepared in one step at room temperature, without any surfactant or mediating reagent.
Chemical Modification of SWCNT and VGCF by Radical Addition Reaction
Authors: Gunji Takahiro , Akazawa Minako , Arimitsu Koji , Abe Yoshimoto 
Published: May 2006

Abstract
Single wall carbon nanotubes (SWCNTs) and vapor growth carbon fibers (VGCFs) were chemically modified by radical reactions with 2,2′-azobis(isobutyronitrile) (AIBN) and 4,4′-azobis(4-cyanovaleric acid) (ACVA) in o-dichlorobenzene. The modification was monitored by infrared and Raman spectra and differential thermal gravimetry. These spectral and analytical data supported the chemical modification of SWCNTs and VGCFs by a simple and clean procedure. AIBN-modified SWCNTs and VGCFs were well dispersed in organic solvents such as methanol, tetrahydrofuran, and chloroform. In contrast, ACVA-modified SWCNTs and VGCFs were dispersed in water.
Organogel Formation by Self-assembly of Ag(I) and Mono-urea Derivatives Containing Pyridyl Group
Authors: Arai Sadao , Imazu Kanako , Kusuda Shiho , Yoshihama Isao , Tonegawa Masami , Nishimura Yukihiro , Kitahara Kei-ichi , Oishi Shigero , Takemura Tetsuo 
Published: May 2006

Abstract
The mono-urea derivative 3 derived from 4-(2-aminoethyl)pyridine and dodecyl isocyanate gelled aromatic solvents, such as p-xylene, tetralin, and benzene, in the presence of Ag(I). The complex formation by the coordination of two equivalents of mono-urea 3 to Ag(I) and the intermolecular hydrogen bonding between urea groups plays important roles for the fibrous self-assembly followed by the gelation.
Adsorption and Possible Luminescence Detection of Nonylphenol by Eu3+–Smectites
Authors: Okada Tomohiko , Ehara Yusuke , Ogawa Makoto 
Published: May 2006

Abstract
4-Nonylphenol was effectively adsorbed on Eu3+–smectites, which were prepared by cation exchange reactions of a natural montmorillonite and a synthetic saponite with Eu3+ chloride, from aqueous solutions. The appearance of luminescence bands of Eu3+ by the excitation of the adsorbed 4-nonylphenol was also observed.
A Route to Redox-active Nanoparticle-cored Dendrimers: Post-encapsulation of Ferrocene
Authors: Shon Young-Seok , Choi Daeock 
Published: May 2006

Abstract
Redox-active nanoparticle-cored dendrimers were synthesized by a stepwise reaction, in which synthesis of functionalized nanoparticles was followed by organic reactions to build dendritic architecture around a nanoparticle core. Incorporation of redox molecules on the surface of nanoparticles resulted in the formation of a redox-active nanoparticle-cored dendrimer.
Heating Effect of Plasma Catalytic Reaction on the CH4 Reforming of CO2 over Ni/γ-Al2O3 Catalyst in Dielectric-barrier Discharge Reactor
Authors: Lee Hwaung , Song Hyung Keun , Min Byoung Ryul 
Published: May 2006

Abstract
CH4 reforming of CO2 reaction for producing synthesis gas (syngas) was performed using dielectric-barrier discharge (DBD) with catalyst. Ni/γ-Al2O3 was used as a catalyst. To investigate the effect of reaction temperature, extra heating was applied outside of the plasma reactor. When supplied extra heating, pure syngas could be obtained only at 573 K. It is a noticeable result comparing with pure catalytic reaction or plasma reaction only.
A Series of Polymorphs with Different Colors in Fluorescent 2,5-Diamino-3,6-dicyanopyrazine Dyes
Authors: Matsumoto Shinya , Uchida Yoko , Yanagita Mitsuhiro 
Published: May 2006

Abstract
We found a series of polymorphs with different colors in 2,5-diamino-3,6-dicyanopyrazine dyes. Their color difference was found to be caused by conformational change in the crystals, not by exciton interactions.
Comparative outcomes of radiofrequency endoluminal ablation, invagination stripping, and cryostripping in the treatment of great saphenous vein insufficiency
Authors: Stötter L , Schaaf I , Bockelbrink A 
Published: May 2006

Objective: Prospective, randomized comparison of short-term and one-year postoperative outcomes after radiofrequency endoluminal ablation (REA) of the great saphenous vein (GSV), saphenofemoral junction (SFJ) ligation with extended tributary ligation and invagination GSV stripping, and SFJ ligation with extended tributary ligation and GSV cryostripping. Methods: In all, 60 consenting patients were randomly allocated to three groups and treated contemporaneously over a nine-month period. Clinical, duplex Doppler, analogue scale pain scoring and activity impairment assessments were performed one day postoperatively, and after one, two, and six weeks, and then repeated after one year, adding patient satisfaction scoring and the CIVIQ 2 quality-of-life questionnaire, specifically designed for lower limb venous insufficiency. Results: Immediate success was achieved in 19/20 REA limbs with one open segment that subsequently spontaneously closed, in 20/20 invagination stripping limbs, and in 18/20 cryostripped limbs, two having residual open segments. Cumulative up to six-week impairment scores, cumulative up to six-week pain scores, and time to return to full activity were all statistically superior for REA patients. At one year, segmental recanalization on less than 10 cm was detected in two REA patients, and for all REA patients the GSV trunk was sonographically no longer visible, beginning from 10 cm below the SFJ. REA patients continued to be significantly more satisfied with both their operative procedures and the cosmetic appearance of their treated lower extremity compared with patients in the two other treatment cohorts. Conclusion: REA offers significant short-term, patient-oriented advantages over extended ligation and invagination or cryostripping through one year.
Audit of venous thromboembolic prophylaxis in emergency general surgical admissions
Authors: Sinha I , Galland R B 
Published: May 2006

Objective: The aim was to audit venous thromboembolic disease (VTE) prophylaxis in emergency surgical admissions and, given the reducing number of available surgical beds, to compare protocol violation rates between surgical and outlying wards. Method: Study 1: Prospective data collected on VTE prophylaxis in emergency surgical patients over a two-week period during or after the post-take ward round. Provisional diagnoses were recorded and drug charts were reviewed looking for prescription of standard unfractionated heparin 5000 IU and/or thromboembolic deterrent stockings. Following presentation at the governance meeting, departmental protocols were circulated to the emergency surgical unit and outlying wards that received emergency surgical patients. Study 2: Carried out two months later. Data on VTE prophylaxis collected over a two-week period in emergency surgical admissions in the same manner as study 1. Results: Study 1: A total of 70 patients were studied, 42 of which were women. The median age of the group was 47 years (range 19–90). There were 36 patients (51.2%) who violated VTE prophylaxis protocol. Of the 60 patients admitted to surgical wards, 29 violated VTE protocol (48.3%). Of the 10 patients admitted to outlying wards, seven violated VTE protocol (70%). This difference was not statistically significant. Study 2: A total of 70 patients were studied, 40 of which were women. The median age was 46 years (range 17–101). Eleven patients (15.7%) violated VTE prophylaxis recommendations. This improvement was statistically significant, P<0.0001. Some 56 patients were admitted to general surgical wards; nine violated VTE protocol (16.1%). In the fourteen patients admitted to outlying wards, there were two protocol violations (14.3%). This difference was not statistically significant. Conclusions: VTE is a potentially fatal complication of hospital admission. This audit highlighted that VTE prophylaxis rates in our emergency admissions were unacceptable at 51.2%, but were improved through audit and clinical governance. No significant difference in protocol violation was found between surgical and outlying wards. In the absence of national guidelines, VTE prophylaxis is the responsibility of individual general surgical departments and requires a documented, circulated departmental protocol, education of staff and regular audit to ensure appropriate compliance.
The morphology of the varicose short saphenous system
Authors: Fowkes L A , Darke S G 
Published: May 2006

Objective: Surgery for the varicose short saphenous vein (SSV) remains unsatisfactory. Specific problems include locating the saphenopopliteal junction (SPJ) and whether the trunk should be stripped. Recurrence rates are high. The objective was to review the morphology of varicose SSV and to address these aspects. Methods: Retrospective study of consecutive patients scheduled for SSV surgery based on initial continuous wave Doppler assessment. Detailed analysis of preoperative duplex ultrasound examinations with quantified reflux. Results: A total of 56 limbs (unilateral) were studied, male to female ratio was 18:38 and mean age was 51 years. SPJ: severe reflux in 47, mean diameter 8.1 mm (all above the skin crease [mean 2.7 cm]). Reflux was 'focal', being confined to the peri-junctional area with normal sized and competent distal short saphenous trunks in 29. In the remainder, incompetence was 'complete' with dilatation and reflux of the entire system. In only one limb did varicosities arise distally from a proximally competent system. Long saphenous vein ( LSV): coexistent reflux in 17, with communications with the SSV in 11. Deep reflux: at least one segment of deep reflux was found in 24 limbs. In this small study, no significant association with other morphology was found apart from 'complete' SSV reflux. Conclusion: The SPJ is usually severely incompetent, enlarged and sited above the skin crease. The morphology of the varicose SSV exhibits important differences from the LSV. In over half, incompetence is 'focal', confined to the peri-junctional vein and the distal trunk is competent suggesting a case for selective trunk stripping. Varicosities arising from a distally incompetent short saphenous trunk are uncommon.
Venous haemodynamic effects of anti-thromboembolism stockings
Authors: Tan J , Lockhart S , Smith A , Burnand K 
Published: May 2006

Objective: The aim of this study was to assess the haemodynamic changes in the deep veins of 13 volunteers, following application of 13 made-to-measure graduated compression stockings all designed to exert different compression gradients along the limb. Methods: The compression gradients were designed to apply pressures from 12–22 mmHg at the ankle to 9–20 mmHg at the calf and 5–10 mmHg at the thigh. These had been laboratory tested by the Hosiery Pressure Tester Mark II (HATRA). A medical stocking tester (MST) was subsequently used to measure the actual pressure measurements on the volunteers. A duplex scanner was used to measure the venous velocity in the deep veins at predetermined sites. Results: The application of all the stockings increased the mean velocity in the popliteal vein by 38.7% (confidence interval [CI] 8–64%, P<0.01) but produced only a slight statistically insignificant increase in velocity in the femoral vein. No particular stocking profile gave significantly better results. A good correlation was found between the MST and HATRA tester measurements of the stocking pressures at the ankle and calf, but the MST method usually recorded higher pressures for the thigh measurements. Conclusions: All profiles of graduated stockings appear to increase the velocity of blood in the deep veins above the knee, but only four pressure profiles (average 16.5, 14 and 6 mmHg) produced significant increases in velocity. There was no evidence to suggest that any one specific compression profile was superior to others at increasing the venous velocity in the popliteal vein.
Exercise with compression stockings improves reflux in patients with mild chronic venous insufficiency
Authors: Zajkowski P J , Draper T , Bloom J , Henke P K , Wakefield T W 
Published: May 2006

Purpose: This study evaluates the effectiveness of calf muscle strengthening with compression stockings on the haemodynamics in patients with venous disease. Method: Patients were assigned to a protocol of aggressive management of their chronic venous insufficiency (CVI) including compression stockings (Jobst knee high, 30–40 mmHg ankle), intermittent leg elevation, and a supervised calf muscle strengthening programme. Patients underwent baseline air plethysmography (APG) with and without stockings (T1) and SF-12, Aberdeen varicose vein questionnaire and venous severity score. Exercise sessions included a total of 18, 1 h supervised sessions, 2–3 times per week, consisting of 15 min on treadmill, 10 min on a Stairmaster, 10 min on a Nustep, and 5 min on an airdyne bicycle and lower body strength training. The sessions were supervised by an exercise physiologist. At completion, patients underwent a second APG (T2) and a third (T3) one month later, as well as answering questionnaires. A final venous severity score was assigned. Results: Eleven patients (7M, 4F), 22 limbs, 14 with CVI and eight without CVI, mean age 60, made up this study. Only two patients suffered from postphlebitic syndrome. In all, 10/11 subjects completed the entire protocol. Although no significant differences were noted in any of the APG parameters between T1 and T2 or T2 and T3, there were significant differences when segregating into C2 ( n = 6 patients with eight involved limbs) and C4, 5 ( n = 5 patients with six involved limbs). Concerning the affected extremities, statistically significant decreases in venous volume (VV) with stockings on between T1 and T2, which reverted back to baseline at T3, and in venous filling index (VFI) between T2 and T3 without stockings were noted ( P<0.05) in C2 limbs. Similar findings were not observed in the C4, C5 limbs, with actual increases in these parameters. Greater increases in ejection fraction were noted in C2 limbs than in C4, C5 limbs. Despite the decrease in reflux in C2 limbs, residual volume fraction (RVF) increased in C2 limbs at T2 both with ( P<0.05) and without stockings, while it decreased in C4, C5 limbs with stockings in place. Finally, outflow fraction (OF) increased only in C2 limbs without stockings in place. Regarding the other parameters, all patients noted improvement in swelling by Aberdeen questionnaire, physical health was improved by SF-12 and patients lost a mean of 3.8 lb of weight. Conclusions: An exercise programme along with compression stockings resulted in a decrease in reflux, especially during the supervised exercise programme, in patients with mild (C2) chronic venous disease. For more extensive disease (C4, C5), the programme tended to decrease RVF.