bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fish skin as a model membrane: structure and characteristics
Authors: Konrádsdóttir Fífa , Loftsson Thorsteinn , Sigfússon Sigurdur Dadi 
Published: June 2009

Abstract

Objectives
Synthetic and cell-based membranes are frequently used during drug formulation development for the assessment of drug availability. However, most of the currently used membranes do not mimic mucosal membranes well, especially the aqueous mucous layer of the membranes. In this study we evaluated catfish (Anarichas lupus L) skin as a model membrane.

Method
Permeation of hydrocortisone, lidocaine hydrochloride, benzocaine, diethyl-stilbestrol, naproxen, picric acid and sodium nitrate through skin from a freshly caught catfish was determined in Franz diffusion cells.

Key findings
Both lipophilic and hydrophilic molecules permeate through catfish skin via hydrated channels or aqueous pores. No correlation was observed between the octanol/water partition coefficient of the permeating molecules and their permeability coefficient through the skin. Permeation through catfish skin was found to be diffusion controlled.

Conclusions
The results suggest that permeation through the fish skin proceeds via a diffusion-controlled process, a process that is similar to drug permeation through the aqueous mucous layer of a mucosal membrane. In addition, the fish skin, with its collagen matrix structure, appears to possess similar properties to the eye sclera.
Pharmacokinetic comparison of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia: influence of disease state
Authors: Qin Feng , Huang Xi , Zhang Hong-Min , Ren Ping 
Published: June 2009

Abstract

Objectives
An investigation has been designed and conducted to compare the pharmaco-kinetics of puerarin after oral administration of Jiawei-Xiaoyao-San to healthy volunteers and to patients with functional dyspepsia.

Methods
Quantification of puerarin in serum was achieved using a simple and rapid HPLC method for pharmacokinetic study.

Key findings
After oral administration of decoctions of Jiawei-Xiaoyao-San to healthy volunteers and patients with functional dyspepsia, puerarin was absorbed and reached a maximum concentration of 56.47 ± 15.60 and 29.40 ± 8.89 ng/ml at 51.00 ± 8.22 and 50.00 ± 12.25 min, respectively. Compared with the value of AUC0–360 (5.55 ± 1.47 μg/ml min) in healthy volunteers, a smaller value of AUC0–360 (3.35 ± 1.17 μg/ml min) was observed in patients with functional dyspepsia.

Conclusions
There were statistically significant differences in the pharmacokinetic parameters of puerarin including the values for Cmax, AUC0–360, Cl/F and MRT0–360 between healthy volunteers and patients with functional dyspepsia. The pharmacokinetic parameters showed that functional dyspepsia reduced the absorption of puerarin after oral administration of Jiawei-Xiaoyao-San.
Stability of oleuropein in the human proximal gut
Authors: Markopoulos Constantinos , Vertzoni Maria , Agalias Apostolos , Magiatis Prokopios , Reppas Christos 
Published: June 2009

Abstract

Objectives
We aimed to assess the intralumenal stability of oleuropein in human gastric and small intestinal contents. We additionally aimed to assess the stability characteristics of oleuropein in media simulating the intralumenal conditions.

Methods
The intralumenal stability of oleuropein was assessed in aspirates from the stomach and the upper small intestine of healthy volunteers collected under both fasted and fed state conditions and in media simulating the intralumenal environment.

Key findings
Oleuropein degraded in aspirates collected in the fasted state. When the initial concentration was about 50 μg/ml (close to expected intragastric concentration after single dose of commercially available products of oleuropein) the mean zero-order half-life of oleuropein in aspirates collected from the fasted small intestine was estimated to be 3.14 ± 0.08 h at 37°C (i.e. after oral administration in the fasted state, a substantial fraction of oleuropein degrades before reaching the intestinal mucosa). In contrast, oleuropein was stable in aspirates collected from the fed stomach; in small intestinal contents aspirated in the fed state the estimated zero-order degradation half-life was at least 12 h.

Conclusions
These data suggest that oleuropein should not have substantial intralumenal stability problems when administered in the fed state. Data collected in media simulating the intragastric and intraintestinal environment suggest that pH affects the stability of oleuropein only at low pH values (of about 2). At higher pHs degradation characteristics are at least partly affected by the presence of other scavengers of reactive oxygen species in the medium.
Metabolism of captopril carboxyl ester derivatives for percutaneous absorption
Authors: Gullick Darren R , Ingram Matthew J , Pugh W John , Cox Paul A , Gard Paul , Smart John D , Moss Gary P 
Published: June 2009

AbstractObjectivesTo determine the metabolism of captopril n-carboxyl derivatives and how this may impact on their use as transdermal prodrugs. The pharmacological activity of the ester derivatives was also characterised in order to compare the angiotensin converting enzyme inhibitory potency of the derivatives compared with the parent drug, captopril.MethodsThe metabolism rates of the ester derivatives were determined in vitro (using porcine liver esterase and porcine ear skin) and in silico (using molecular modelling to investigate the potential to predict metabolism).Key findingsRelatively slow pseudo first-order metabolism of the prodrugs was observed, with the ethyl ester displaying the highest rate of metabolism. A strong relationship was established between in-vitro methods, while in-silico methods support the use of in-vitro methods and highlight the potential of in-silico techniques to predict metabolism. All the prodrugs behaved as angiotensin converting enzyme inhibitors, with the methyl ester displaying optimum inhibition.ConclusionsIn-vitro porcine liver esterase metabolism rates inform in-vitro skin rates well, and in-silico interaction energies relate well to both. Thus, in-silico methods may be developed that include interaction energies to predict metabolism rates.
Pectin/Kollicoat SR30D isolated films for colonic delivery [I]: a comparison of normal and colitis-induced models to assess the efficiency of microbially triggered drug delivery
Authors: Wei He , Li-Fang Fan , Yong-Zhen Chang , Bai Xiang , Qing Du , Min Bai , Feng Wang , Min Qing , De-Ying Cao 
Published: June 2009

AbstractObjectivesThe purpose of the study was to evaluate digestion of pectin/Kollicoat SR30D free films for colonic delivery in vitro and in vivo.MethodsFree films containing different ratios of pectin to Kollicoat SR30D were prepared by casting/solvent evaporation method. An in-vitro comparison of swelling, degradation and permeability of the free films was carried out in simulated colon fluids containing caecal contents from normal rats with colitis induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) or oxazolone. A comparative in-vivo evaluation of degradation was also conducted in normal and colitis-induced model rats.Key findingsThe pectin within the mixed films was susceptible to rat colonic bacterial enzymes. The extent of digestion correlated with the amount of pectin present within the film. In vitro, the swelling index, drug permeability and extent of film digestion in simulated colon fluids with caecal contents obtained from normal rats were higher than from TNBS- or oxazolone-induced model rats, whereas in-vivo degradation was similar in the three groups of rats. The pectin/Kollicoat SR30D free films were completely degraded in the colitis-induced rats.ConclusionsPectic/Kollicoat SR30D films may be useful as coatings to target delivery of drugs to the colon.
Coumarins permeability in Caco-2 cell model
Authors: Galkin Anna , Fallarero Adyary , Vuorela Pia M 
Published: June 2009

AbstractObjectivesThe presence of coumarins in human diet, their multiple pharma***ćological properties and occurrence in various herbal remedies represent significant reasons to explore their membrane permeability, as a first event contributing to coumarins oral bioavailability. Thus, we evaluated the permeability and cytotoxicity of 18 coumarins, with different substitution patterns involving OH, OCH3 and CH3 groups.MethodsA modified Caco-2 permeability model was used, in which the permeability test is performed with a robotic workstation and cells are grown on 96-well plates for 7 days.Key findingsAll studied coumarins were highly permeable, with calculated Papp values that varied within 4.1 times 10−5 to 2.1 times 10−4 in apical to basolateral studies and within 1.8 times 10−5 to 7.0 times 10−5 in basolateral to apical studies. The efflux ratio remained in all cases below 1. It was demonstrated that the type and position of substituents contributed more to the permeability than the number of substituents.ConclusionsThe results allowed us to predict that these coumarins are well absorbed in the gut lumen and efflux is not limiting the absorption. Five coumarins had an influence on the mitochondrial function of Caco-2 cells (1 &lt; 80%, 4 &gt; 120%), according to the WST-1 cytotoxicity test, but this does not seem to affect the permeability of the compounds.
Oxidative stress, nitric oxide and prostaglandin E2 levels in the gastrointestinal tract of aging rats
Authors: Mármol Frederic , Sánchez Juan , López Diego , Martínez Nuria , Mitjavila Maria Teresa , Puig-Parellada Pere 
Published: June 2009

AbstractObjectivesTo evaluate the presence of oxidative stress and alterations in the levels of two cytoprotective agents, prostaglandin E2 and nitric oxide, in the gastrointestinal tract of aging rats.MethodsThe production of superoxide anion, lipid peroxides, levels of superoxide dismutase and catalase, and production of prostaglandin E2 and nitric oxide in the stomach and duodenum of rats were determined at 1.5, 3, 12, 18 and 24 months of age.Key findingsOxidative stress was present in the stomach of the old rats (24 months), whereas prostaglandin E2 and nitric oxide production remained stable at 18 and 24 months. In the duodenum, no oxidative stress was observed at 24 months, but at 18 months, an increase in superoxide anion levels was detected. Prostaglandin E2 remained constant in the aged rats but nitric oxide decreased significantly at 24 months.ConclusionsThe absence of macroscopic gastric injury throughout the gastrointestinal tract indicates that the oxidative stress in the stomach and the significant decrease of nitric oxide in the duodenum in the old rats are not sufficient to disrupt the mucosal defence network. The results support the notion that the disruption of the mucosal network is essentially regulated by the cytoprotective agents prostaglandin E2 and nitric oxide, and that injury appears only when both substances are concurrently reduced.
Animal studies supporting the inhibition of mast cell activation byEriobotrya japonicaseed extract
Authors: Onogawa Masahide , Sun Guangchen , Takuma Daisuke , Hamada Atsuhide , Yokota Junko , Yoshioka Saburo , Kusunose Masahiko , Miyamura Mitsuhiko , Kyotani Shojiro , Nishioka Yutaka 
Published: June 2009

AbstractObjectivesThe potent antioxidant activity of Eriobotrya japonica seed extract (ESE) and its usefulness in the prevention and treatment of various disorders has been reported previously. Its antioxidant activity associated with β-sitosterol and polyphenols contained in the extract was also validated. In this study, anti-allergic activity of Eriobotrya japonica seed extract was investigated.MethodsThe inhibition of histamine release-mediated type 1 allergy by Eriobotrya japonica seed extract was used as an index.Key findingsThe administration of this extract inhibited histamine release from rat mast cells, suggesting its usefulness in allergic disease treatment. In an experiment using a guineapig allergic rhinitis model, this extract reduced the frequency of sneezing and nose-scratching.ConclusionsThese results suggest that Eriobotrya japonica seed extract may contribute to the relief of allergic disease-related symptoms.
Anticoagulation: Effect of a Warfarin Adherence Aid on Anticoagulation Control in an Inner-City Anticoagulation Clinic Population
Authors: Nochowitz Beth , Shapiro Nancy L , Nutescu Edith A , Cavallari Larisa H 
Published: June 2009

Background: Poor adherence to warfarin therapy is a major contributor to subtherapeutic anticoagulation. Objective: To determine whether use of a monthly medication organizer, filled at each clinic visit, improves anticoagulation control among warfarin-treated patients. Methods: Patients who had a history of nonadherence to warfarin and were attending an inner-city anticoagulation clinic were enrolled in this prospective cohort study and provided with a 28-day medication organizer. Patients were instructed to bring their organizers and warfarin tablets to each anticoagulation clinic visit over the following 3 months. At each visit, the international normalized ratio (INR) was measured, warfarin adherence was assessed, and the organizer was filled with the prescribed warfarin regimen until the next scheduled visit. Data on warfarin adherence and INR values during the 3 months prior to enrollment were collected from medical records and compared with postenrollment data. Results: Thirteen patients were enrolled and completed at least one postenrollment clinic visit. Adherence to warfarin therapy improved with use of the medication organizer (mean ± SD preenrollment 55 ± 25%, postenrollment 67 ± 21%; p = 0.06). There was a significant decrease in the proportion of subtherapeutic INR values (60 ± 25% to 35 ± 29%; p = 0.04) and a significant improvement in the percent of time spent within the therapeutic INR range (32 ± 22% to 56 ± 28%; p = 0.03) after enrollment. Conclusions: Use of a monthly medication organizer significantly reduced the percent of subtherapeutic INR values and improved the time spent within the therapeutic anticoagulation range among previously nonadherent patients managed in an inner-city anticoagulation clinic.
Influence of Local Site Conditions on the Reliability of Fundamental-Mode Surface Wave Inversion Methods
Authors: Rosenblad Brent L. , Li Jianhua 
Published: June 2009

Abstract
The development of reliable shear wave velocity (VS) profiles from surface wave velocity measurements requires compatibility between the measured and theoretical dispersion curves used in the inversion procedure. The most common approach in geotechnical applications is to use a fundamental-mode theoretical dispersion curve based on the assumption that the measured dispersion curve is representative of the fundamental mode of surface wave propagation. Analyses of low-frequency surface wave measurements presented in this paper show that this widespread assumption is invalid at low frequencies (long wavelengths) for some profile conditions. Results are presented from measurements performed at two deep soil sites in the central United States where surface wave analyses were performed using both the common fundamental-mode approach as well as an “effective-velocity” approach. At one site these two methods produced essentially the same estimate of the VS profile, while at the second site the estimated VS values at depth differed by more than 40 %. Using soil profile information for these sites and simulations of surface wave propagation, it is shown that the shallower depth to a higher-velocity formation at the second site created dominant higher-mode energy at wavelengths of 300–600 m, resulting in an overestimation of deep VS values.
Imazapyr Absorption and Translocation in Northern Red Oak and Red Maple as Affected by Herbicide Formulation and the Adjuvant Methylated Seed Oil
Authors: Bernards Mark L. , Penner Donald , Michael Jan 
Published: June 2009

Abstract
Imazapyr-based herbicides are important in removing deciduous hardwood species from conifer plantations. Imazapyr can be applied as a site preparation (pre-establishment) application or as a postestablishment herbaceous or release application. Herbicide efficacy is dependent, in part, on how much herbicide is absorbed and translocated throughout the target weed species. Herbicide absorption can be strongly influenced by herbicide formulation or tank-mix adjuvants. Little data are available on imazapyr absorption and translocation by woody species. The objective of this research was to compare the absorption and translocation of six experimental formulations of imazapyr to a commercial formulation, Chopper®, with and without methylated seed oil (MSO), in northern red oak (Quercus rubra L.) and red maple (Acer rubrum L.). Saplings of both species were grown in the greenhouse until they reached a height of approximately 1 m. Trees were blocked according to size, and treatments were randomly assigned within blocks. For the absorption study, five leaves were selected per plant and received two 1-μL drops of 14C-imazapyr-labeled solution. Leaves were rinsed at 2, 8, 24, 72, and 144 h after treatment (HAT). Absorption was quantified as 14C imazapyr that was not collected in the rinse solution. All experimental formulations that were tank-mixed with MSO increased absorption on oak compared to Chopper+MSO. Not all experimental formulations increased absorption in maple, and absorption data were highly variable. Absorption continued for at least 72 HAT in both species for most formulations. For the translocation study, one leaf was treated with two 1-μL drops of 14C-imazapyr-labeled solution. The leaf was rinsed at 144 HAT, and the plant was harvested and divided into sections: above treated leaf, treated leaf, below treated leaf, and roots. The majority (52–91 %) of the applied imazapyr remained in the treated leaf. More imazapyr was translocated from the leaf of red oak than red maple. Translocated 14C accumulated in the tissue above the treated leaf (3–13 % of absorbed) and in the roots (3–34 %). Including the adjuvant MSO and optimizing the herbicide formulation increased the absorption of imazapyr in red maple and northern red oak.
Understanding the Molecular Surface Charges of Asphalt or Clay Particles and Application in the Transportation and Oil Sands Industries
Authors: Ho Susanna , Zanzotto Ludo 
Published: June 2009

AbstractAsphalt binder is a mixture of many different types of molecules. At the molecular level, one can visualize the asphalt binder as a colloidal system with asphaltene molecules dispersed in oil with naphthene and polar aromatics. The functional groups of the asphaltene molecules are essential in keeping them dispersed as colloids. These polar functional groups include alcohol, amine, carboxylic, and phenolic groups. The polarity of asphalt molecules are very important in allowing them to adhere to the inorganic aggregates, which also bear charges at the surface. The application of this understanding to the aging of paving asphalt, asphalt modification, the Superpave direct tension test, aggregate specific gravity determination, ash as modifiers in asphalt, low-volume road chemical stabilization, and the oil sands industry are discussed.
Calibration Procedures for the Intelligent Asphalt Compaction Analyzer
Authors: Commuri Sesh , Mai Anh , Zaman Musharraf 
Published: June 2009

Abstract
The intelligent asphalt compaction analyzer (IACA) is a device based on neural network technology that can measure the density of an asphalt pavement continuously in real time during its construction. It was shown during limited field trials that the IACA could, in real time, measure the density of an asphalt pavement during its construction with accuracy comparable to existing point-wise measurement technologies. In this paper, the procedure to calibrate the IACA and the validation of the performance, i.e., accuracy of density measurements, are addressed. The results demonstrate that the IACA can be used to determine the density of the asphalt mat during compaction with an accuracy needed for quality control operations in the field.
INVESTIGATION OF TIDAL PHENOMENA IN THE CLYDE ESTUARY, USING A SCALE MODEL. (INCLUDES PHOTOGRAPH).
Authors: THOM A S 
Published: June 2009

Synopsis. The model was constructed to horizontal and vertical scales of 1 : 5,280 and 1 : 115 respectively, and the bed was finished with a layer of cement-sand mortar. Tides were generated by a displacer, moved by mechanism designed on the principle of Lord Kelvin's tide-predicting machine to reproduce the spring/neap cycle. A hump developed on the curve of the rising spring tide in the model at the same level as that on the estuary-tide, becoming more pronounced as the wave advanced upstream. Reclamation of large areas of land on the model caused little increase in range at Glasgow. Observations taken immediately after stopping the motion of the displacer indicated that the natural period of the model was 4 hours—about one-third of the tidal period. Harmonic analysis of tide curves in the estuary showed that the amplitudes of all the harmonic components increased with distance from the estuary mouth, and that the rate of increase of the third harmonic component was greater than that of the second or fourth. The pronounced hump on the tide curve at Glasgow was caused by magnification of the third harmonic. Analysis indicated that the mean water-level at Glasgow was considerably above that at Gourock.
A METHOD OF DETERMINING THE SECONDARY STRESSES IN CYLINDRICAL SHELL ROOFS.
Authors: MARSHALL W T 
Published: June 2009

Synopsis. The membrane theory for the stresses in thin shells is based on the fundamental assumption that there is no change of shape of the shell on loading. In shell-roof construction, however, there must be a deflexion of the edge tie-beam, with resultant secondary stresses in the shell. Some solutions have been given for this problem (outstanding being those of Dischinger, Finsterwalder, Schorer, and Jenkins), but many of them are very difficult to follow and are of doubtful value to engineers because of the lack of numerical examples. The first part of this Paper is devoted to a summary of the work of those previous investigators. Dischinger's solution of the problem shows that the longitudinal stress-distribution in the cylindrical portion of the shell is almost equal to that obtained by considering the complete shell as a beam spanning between the columns at the gable ends. The Author has utilized this stress distribution as a means of determining the constants of integration in Schorer's method of analysis. The “beam” method described in the Paper entails less work than other methods and has the advantage that a slide-rule can be employed for most of the calculations. The Paper concludes with a section giving an example which shows the application of the method to the design of a roof.