bluuebunny/crossref_metadata_2025_split huggingface dataset:
Secondary Succession and Indigenous Management in Semideciduous Forest Fallows of the Amazon Basin1
Authors: Toledo Marisol , Salick Jan 
Published: December 2005

ABSTRACTTo the discussion on secondary succession in tropical forests, we bring data on three under‐addressed issues: understory as well as overstory changes, continuous as opposed to phase changes, and integration of forest succession with indigenous fallow management and plant uses. Changes in vegetation structure and species composition were analyzed in secondary forests following swidden agriculture in a semideciduous forest of Bolivian lowlands. Twenty‐eight fallows, stratified by four successional stages (early = 1–5 yr, intermediate = 6–10 yr, advanced = 12–20 yr, and older = 22–36 yr), and ten stands of mature forests were sampled. The overstory (plants ≥5 cm diameter at breast height [DBH]) was sampled using a 20 × 50 m plot and the understory (plants <5 cm DBH) in three nested 2 × 5 m subplots. Semistructured interviews provided information on fallow management. Canopy height, basal area, and liana density of the overstory increased with secondary forest age. The early stage had the lowest species density and diversity in the overstory, but the highest diversity in the understory. Species composition and abundance differentiated mature forests and early successional stage from other successional stages; however, species showed individualistic responses across the temporal gradient. A total of 123 of 280 species were useful with edible, medicinal, and construction plants being the most abundant for both over‐ and understories. Most of Los Gwarayo preferred mature forests for making new swidden, while fallows were valuable for crops, useful species, and regenerating timber species.
Distribution of gamma-ray burst ejecta energy with Lorentz factor
Authors: Granot Jonathan , Kumar Pawan 
Published: December 2005

Abstract
The early X-ray afterglow for a significant number of gamma-ray bursts detected by the Swift satellite is observed to have a phase of very slow flux decline with time (Fν ∝ t−α with 0.2 ≲α≲ 0.8) for 102.5≲t≲ 104 s, while the subsequent decline is the usual 1 ≲α3≲ 1.5 behaviour, which was seen in the pre-Swift era. We show that this behaviour is a natural consequence of a small spread in the Lorentz factor of the ejecta, by a factor of ∼2–4, where the slower ejecta gradually catch up with the shocked external medium, thus increasing the energy of the forward shock and delaying its deceleration. The end of the ‘shallow’ flux decay stage marks the beginning of the Blandford–McKee self-similar external shock evolution. This suggests that most of the energy in the relativistic outflow is in material with a Lorentz factor of ∼30–50.
On the Hysteresis in Moisture Storage and Conductivity Measured by the Instantaneous Profile Method
Authors: Plagge Rudolf , Scheffler Gregor , Grunewald John , Funk Max 
Published: December 2005

The relative humidity (or the capillary pressure) and volumetric water content can be determined at specific locations inside a porous medium by means of the proposed instantaneous profile method (IPM). The measurements are carried out with temperature and relative humidity (RH) sensors as well as with time domain reflectometry probes during the whole duration of the experiment. Thus, the IPM allows a transient measurement of the moisture retention characteristic. In addition, from the spatial and temporal distributions of moisture content and RH one may calculate the moisture conductivity as a function of moisture content and RH as well. The adsorption and successive desorption experiments presented in this article have been performed on calcium silicate (a capillary active material). The results show a hysteretic behavior that appears to depend on the nature of the process. The moisture conductivity as function of RH shows a significant hystereses; however, the moisture conductivity in relation to the moisture content appears to be non-hysteretic.
Statins and osteoporosis: new role for old drugs
Authors: Jadhav Satyawan B , Jain Girish Kumar 
Published: December 2005

AbstractOsteoporosis is the most common bone disease, affecting millions of people worldwide and leading to significant morbidity and high expenditure. Most of the current therapies available for its treatment are limited to the prevention or slowing down of bone loss rather than enhancing bone formation. Recent discovery of statins (HMG-CoA reductase inhibitors) as bone anabolic agents has spurred a great deal of interest among both basic and clinical bone researchers. In-vitro and some animal studies suggest that statins increase the bone mass by enhancing bone morphogenetic protein-2 (BMP-2)-mediated osteoblast expression. Although a limited number of case—control studies suggest that statins may have the potential to reduce the risk of fractures by increasing bone formation, other studies have failed to show a benefit in fracture reduction. Randomized, controlled clinical trials are needed to resolve this conflict. One possible reason for the discrepancy in the results of preclinical, as well as clinical, studies is the liver-specific nature of statins. Considering their high liver specificity and low oral bioavailability, distribution of statins to the bone microenvironment in optimum concentration is questionable. To unravel their exact mechanism and confirm beneficial action on bone, statins should reach the bone microenvironment in optimum concentration. Dose optimization and use of novel controlled drug delivery systems may help in increasing the bioavailability and distribution of statins to the bone microenvironment. Discovery of bone-specific statins or their bone-targeted delivery offers great potential in the treatment of osteoporosis. In this review, we have summarized various preclinical and clinical studies of statins and their action on bone. We have also discussed the possible mechanism of action of statins on bone. Finally, the role of drug delivery systems in confirming and assessing the actual potential of statins as anti-osteoporotic agents is highlighted.
Preliminary investigation of the nasal delivery of liposomal leuprorelin acetate for contraception in rats
Authors: Shahiwala Aliasgar , Misra Ambikanandan 
Published: December 2005

AbstractThe purpose of the study was to investigate the nasal route as a non-invasive alternative for delivery of leuprorelin acetate (leuprolide acetate, LEU) and to achieve an effective concentration of leuprorelin acetate in blood after nasal administration for contraception in rats. The plain drug solution, physical mixture (plain drug along with constituents of liposomes), or drug encapsulated in either neutral or charged liposomes containing 5 μg leuprorelin acetate were administered to rats through the nasal route. The plain drug solution was administered subcutaneously (s.c.). Simultaneous evaluation was performed on the influence of a mucoadhesive agent (chitosan) on nasal absorption of the plain drug and the liposome-encapsulated drug. Blood samples were taken at regular time intervals and subjected to luteinising hormone (LH) analysis using a specific immunoassay kit. The plasma luteinising hormone concentration vs time data of nasal and subcutaneous treatments were plotted and compared with that of subcutaneous administration. Relative percentage of bioavailability (F) for nasal treatments was calculated from plasma concentration vs time plots. Sperm count and fertility performance studies were carried out for selected formulations in rats. Neutral liposomes (LLEU) and negatively-charged liposomes (LLEUn) showed higher relative percentage of bioavailability (F 27.83 and 21.30%, respectively) as compared with the plain drug and the physical mixture (F 10.89 and 10.96%, respectively) after nasal administration. Hence, work on neutral liposomes was continued. F was further improved after incorporation of chitosan i.e. 10.89 to 49.13% for plain leuprorelin acetate and 27.83 to 88.90% for liposomal leuprorelin acetate formulations. Liposomal chitosan formulation administered nasally and leuprorelin acetate solution subcutaneously achieved complete azoospermia. No implantation sites were observed after the mating of female rats with treated males. It was observed that in the treated female rats, the estrous cycles ceased with the same formulations from the first treatment cycle. The findings of these investigations demonstrated that the bioavailability of the nasally-administered liposomal leuprorelin acetate with chitosan formulation was comparable with that of the subcutaneously administered drug. Complete contraception was obtained in male and female rats that had been treated with either the nasally administered liposomal leuprorelin acetate with chitosan or the subcutaneously administered drug.
Effect of the co-occurring components from green tea on the intestinal absorption and disposition of green tea polyphenols in Caco-2 monolayer model
Authors: Zhang Li , Chow Moses S S , Zuo Zhong 
Published: December 2005

Abstract
This study aimed to investigate the effect of co-occurring components from green tea on the intestinal absorption and disposition of green tea polyphenols (GTPs) using the Caco-2 cell monolayer model. The absorption and secretion transport of the four GTPs, in the form of individual pure compounds, pure compound mixtures and green tea extract, were studied in the Caco-2 cell model. Four GTPs and their metabolites were analysed by HPLC/MS and HPLC coupled with electrochemical detector. The apparent permeability coefficients (Papp) of each compound, as well as the metabolites (mainly sulfation and methylation conjugates) generated, were compared for the different dosing formulations utilized. The results showed that the absorption transport of the four GTPs in different dosing formulations was similar. However, the secretion transport profiles of (-)-epicatechin (EC), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) were altered when the GTP mixture was administered. It was suggested that transporter competition resulting in reduced efflux of EC, as well as metabolic competition resulting in reduced formation of EGC sulfate and methylated EGC sulfate, might be involved during the secretion transport of GTP mixture.
Effects of Transcutol P on the corneal permeability of drugs and evaluation of its ocular irritation of rabbit eyes
Authors: Liu Zhidong , Nie Shufang , Guo Hong , Pan Weisan , Li Jiawei 
Published: December 2005

Abstract
Our purpose was to explore the use of Transcutol P (Trans) in an ocular drug delivery system. The effect of Trans on the corneal permeability of drugs was investigated in-vitro, using isolated rabbit corneas. The ocular irritation of Trans was also tested in rabbits in-vivo. In the presence of Trans, at a concentration of 0.005–0.03%, the maximum increase in the apparent permeability coefficient (Papp) was 1.5, 1.5, 3.0 and 3.3 fold for ribavirin, gatifloxacin, levofloxacin hydrochloride and enoxacin, respectively. However, the Papp value of oxaprozin was reduced in the presence of Trans. The maximum reduction was found to be 2.8 fold at a concentration of 0.03% Trans. The results of the ocular irritation studies showed that Trans was non-irritant at the concentrations studied (0.005–0.03%), while it produced slight irritation at a concentration of 0.05%. It was also found that Trans did not cause any visible ocular damage or abnormal clinical signs involving the cornea, iris or conjunctivae at all concentrations. We concluded that Trans may have potential clinical benefits in improving the ocular drug delivery of hydrophilic compounds.
Chlorzoxazone metabolism is increased in fasted Sprague-Dawley rats
Authors: Wan Jie , Shoaf Susan E , Ernstgård Lena , Song Byoung J 
Published: December 2005

AbstractEarlier data showed that men fasted for 38 h had a reduced rate of chlorzoxazone metabolism, suggesting a decreased level of cytochrome P450 2E1 (CYP2E1). In contrast, the level of CYP2E1 in fasted rats had been shown to be elevated. In this study, we have investigated whether chlorzoxazone metabolism in fasted rats was changed by determining the pharmacokinetics of chlorzoxazone and its metabolite, 6-hydroxychlorzoxazone (6-OHCZ), as a CYP2E1 probe, and by measuring liver CYP2E1 using immunoblot techniques. Chlorzoxazone was administered by gavage (50 mg kg−1) or intravenously (25 mg kg−1) to control (nine for oral and three for intravenous) and 24 h-fasted (nine for oral and four for intravenous) male Sprague-Dawley rats. Following sampling of blood through a jugular vein cannula, chlorzoxazone and 6-OHCZ plasma concentrations were measured by HPLC with UV detection. Pharmacokinetic parameters for chlorzoxazone and 6-OHCZ in each treatment group were determined by model fitting and non-compartmental analysis. In parallel with the increased liver CYP2E1 level, the elimination of chlorzoxazone and 6-OHCZ was significantly increased in fasted rats in the oral and the intravenous study. A multiple analysis of variance covariance analysis and a multiple regression analysis revealed a significant correlation between 1/t½ and CYP2E1 level and aniline hydroxylase activity. However, the correlation between 1/t½ and pentoxyresorufin O-dealkylase, ethoxyresorufin O-dealkylase and erythromycin N-demethylase was not significant. Therefore the contribution of other P450s to chlorzoxazone metabolism seemed to be minor in the concentration range that we tested. In conclusion, fasting rats for 24 h caused a measurable induction of CYP2E1, which produced a significant increase in the rate of chlorzoxazone metabolism and elimination.
Carbamazepine uptake into rat brain following intra-olfactory transport
Authors: Barakat N S , Omar S A , Ahmed A A E 
Published: December 2005

Abstract
Targeting the brain via nasal administration of drugs has been studied frequently over the last few years. In this study, a suitable gel formulation was designed to provide the absorption of a highly lipophilic drug through nasal mucosa. For this purpose, carbamazepine was chosen as the model drug. Hypromellose and Carbopol were used as mucoadhesive polymers in the formulation to increase the residence time of the gel on the mucosa. The objective of this study was to confirm the existence of a transport pathway for a drug (carbamazepine) to the brain directly from the nasal cavity, by comparing the concentration of drug in the brain after intranasal (i.n.), intravenous (i.v.), and oral (p.o.) administration. A statistically significant high level of the drug was found in the brain following intranasal administration compared with the intravenous and oral routes. These findings suggested the existence of a direct transport pathway for carbamazepine from the nasal cavity to the brain. This pathway may represent a new delivery route to the brain and central nervous system of such drugs which are needed in high and rapid concentration in the brain, especially in emergencies.
Characterisation and regulation of E2F-6 and E2F-6b in the rat heart: a potential target for myocardial regeneration?
Authors: Movassagh Mehregan , Bicknell Katrina A , Brooks Gavin 
Published: December 2005

Abstract
The E2F transcription factors are instrumental in regulating cell cycle progression and growth, including that in cardiomyocytes, which exit the cell cycle shortly after birth. E2F-6 has been demonstrated to act as a transcriptional repressor; however, its potential role in normal cardiomyocyte proliferation and hypertrophy has not previously been investigated. Here we report the isolation and characterisation of E2F-6 and E2F-6b in rat cardiomyocytes and consider its potential as a target for myocardial regeneration following injury. At the mRNA level, both rat E2F-6 and the alternatively spliced variant, E2F-6b, were expressed in E18 myocytes and levels were maintained throughout development into adulthood. Interestingly, E2F-6 protein expression was down-regulated during myocyte development suggesting that it is regulated post-transcriptionally in these cells. During myocyte hypertrophy, the mRNA expressions of E2F-6 and E2F-6b were not regulated whereas E2F-6 protein was up-regulated significantly. Indeed, E2F-6 protein expression levels closely parallel the developmental withdrawal of myocytes from the cell cycle and the subsequent reactivation of their cell cycle machinery during hypertrophic growth. Furthermore, depletion of E2F-6, using anti-sense technology, results in death of cultured neonatal myocytes. Taken together, abrogation of E2F-6 expression in neonatal cardiomyocytes leads to a significant decrease in their viability, consistent with the notion that E2F-6 might be required for maintaining normal myocyte growth.
Effect of polypeptides in bee venom on growth inhibition and apoptosis induction of the human hepatoma cell line SMMC-7721 in-vitro and Balb/c nude mice in-vivo
Authors: Hu H , Chen D , Li Y , Zhang X 
Published: December 2005

AbstractPolypeptides in bee venom (PBV) produced a significant growth inhibition against SMMC-7721 human hepatoma cell line. Analysis of the mechanisms of cell death indicated that PBV induced an apoptotic cell death. SMMC-7721 cells exposed to PBV (10.0 μg mL−1) produced an insignificant morphological change. Analysis of the cytotoxicity with the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium) assay confirmed that the cytotoxic effects of PBV were dose- and time-dependent. The result of Ki67 immunohistochemistry demonstrated that the proliferation of SMMC-7721 cells treated with PBV (10.0 μg mL−1) was inhibited. The apoptotic cell death was then confirmed by annexin V, propidium iodide staining and DNA fragmentation analysis. In in-vivo experiments, treatment with PBV (1.5 or 3 mg kg−1) resulted in a significant retardation of SMMC-7721 cell growth in Balb/c nude mice. These findings suggested that PBV could be used as a chemotherapeutic agent against tumours.
Effect of tranilast on matrix metalloproteinase production from neutrophils in-vitro
Authors: Shimizu Toshiyuki , Kanai Ken-Ichi , Kyo Yoshiyuki , Suzaki Harumi , Asano Kazuhito , Hisamitsu Tadashi 
Published: December 2005

Abstract
Tranilast is an anti-allergic agent that blocks the release of chemical mediators, such as histamine and leukotrienes from mast cells, and has been reported to suppress keloid and hypertrophic scar formation. Since matrix metalloproteinases (MMPs) play an essential role in tissue remodelling, this study was undertaken to determine whether tranilast suppresses MMP production from neutrophils after lipopolysaccharide (LPS) stimulation in-vitro. Neutrophils from five healthy donors (1times105 cells/mL) were stimulated with 1.0 μg mL−1 LPS in the presence or absence of various concentrations of tranilast for 24 h. MMP-7, MMP-8, MMP-9 and tissue inhibitor of metalloproteinase (TIMP)-1 levels in the culture supernatants were assayed by ELISA. In addition, the influence of tranilast on MMP mRNA expression and transcriptional factor activation in cells cultured for 12 h and 4 h was also evaluated by reverse transcriptase—polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Tranilast inhibited MMP and TIMP-1 production from neutrophils when cells were treated with the agent at more than 5.0times10−5 m. It also suppressed MMP mRNA expression and transcriptional factor activation induced in neutrophils by LPS stimulation. The results suggest that tranilast inhibits the formation of keloid scarring through the suppression of factors such as MMPs and TIMP, which are essential for tissue remodelling, from inflammatory cells.
Effects of some natural 5-hydroxy-isoflavones on cultured human endothelial cells in presence and absence of hydrogen peroxide
Authors: Paulo Alexandra , Mota-Filipe Helder 
Published: December 2005

Abstract
Due to their biological activity, it has been suggested that consumption of isoflavone-rich diets may prevent prostate and breast cancers, osteoporosis and cardiovascular diseases. Preventive effects of isoflavones on cancer and cardiovascular diseases have been associated with their oestrogenic and antioxidant properties. However, concerns still exist about the potential dangers of consuming high levels of these compounds, since it is known that some of them have cytostatic or cytotoxic properties, depending on the concentration. To evaluate the potential cytotoxic risk and antioxidant benefit of natural 5-hydroxy-isoflavones (5-OH-isoflavones) for human vascular endothelium, the effect of some natural 5-OH-isoflavones was evaluated on cultured human endothelial cells, in the presence and absence of H2O2 (3 mm for 4 h). None of the isoflavones tested were able to prevent oxidative damage to endothelial cells at maximal extracellular concentrations of 1 mm. The low antioxidant capacity of these compounds was also shown by the DPPH (1,1-diphenyl-2-picrylhydrazyl radical) method. On the other hand, genistein and biochanin A, having a free 7-OH group, were toxic to the human endothelial cells in a dose-dependent manner, at concentrations ≥300 μm and ≥ 100 μm, respectively. These results indicate that the non-specific cytotoxic effect of 5-OH-isoflavones is associated with the free 7-OH group. In conclusion, we were not able to show that 5-OH-isoflavones are beneficial to human endothelial cells when the cells were exposed to oxidative stress caused by 3 mm of H2O2, but it can be concluded that consumption of 5-OH-isoflavones is of no direct cytotoxic risk to the human vascular endothelium since toxic concentrations are believed to be unreachable in-vivo.
Antinociceptive properties of coumarins, steroid and dihydrostyryl-2-pyrones from Polygala sabulosa (Polygalaceae) in mice
Authors: Ardenghi Juliana V , Pretto Juliana B , Souza Márcia M , Junior Anildo Cunha , Soldi Cristian , Pizzolatti Moacir Geraldo , Meotti Flavia Carla , Moura Janaína d‘Ávila , Santos Adair R S 
Published: December 2005

Abstract
We have investigated the possible antinociceptive action of the extract, fractions and pure compounds obtained from the whole plant Polygala sabulosa A. W. Bennett (Polygalaceae) in acetic acid-induced visceral pain in mice. Intraperitoneal injection of animals with the hydroalcoholic extract and fractions (CH2Cl2, EtOAc, n-BuOH, aqueous fraction) (1–100 mg kg−1) caused a dose-related and significant inhibition of the acetic acid-induced visceral nociceptive response. The CH2Cl2, EtOAc and n-BuOH fractions were more potent than the hydroalcoholic extract and aqueous fraction. The isolated compounds dihydrostyryl-2-pyrones (1, 2, 3), styryl-2-pyrone (7), α-spinasterol (9), scopoletin (10) and two esters of the coumarin (scopoletin) obtained semisynthetically, acetylscopoletin (10a) and benzoylscopoletin (10b) (0.001–10 mg kg−1), exhibited significant and dose-related antinociceptive effects against acetic acid-induced visceral pain. The results distinguished, for the first time, the extract, fractions and pure compounds obtained from P. sabulosa that produced marked antinociception against the acetic acid-induced visceral nociceptive response, supporting the ethnomedical use of P. sabulosa.