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111.
Simvastatin (SV), a drug of the statin class currently used orally as an anti-cholesterolemic via the inhibition of the 3-hydroxy-3-methyl-glutaryl-Coenzyme A (HMG-CoA) reductase, has been found not only to reduce cholesterol but also to have several other pharmacological actions that might be beneficial in airway inflammatory diseases. Currently, there is no inhalable formulation that could deliver SV to the lungs. In this study, a pressurised metered-dose inhaler (pMDI) solution formulation of SV was manufactured, with ethanol as a co-solvent, and its aerosol performance and physico-chemical properties investigated. A pMDI solution formulation containing SV and 6% w/w ethanol was prepared. This formulation was assessed visually and quantitatively for SV solubility. Furthermore, the aerosol performance (using Andersen Cascade impactor at 28.3 L/min) and active ingredient chemical stability up to 6 months at different storage temperatures, 4 and 25°C, were also evaluated. The physico-chemical properties of the SV solution pMDI were also characterised by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and laser diffraction. The aerosol particles, determined using scanning electron microscopy (SEM), presented a smooth surface morphology and were spherical in shape. The aerosol produced had a fine particle fraction of 30.77 ± 2.44% and a particle size distribution suitable for inhalation drug delivery. Furthermore, the short-term chemical stability showed the formulation to be stable at 4°C for up to 6 months, whilst at 25°C, the formulation was stable up to 3 months. In this study, a respirable and stable SV solution pMDI formulation for inhalation has been presented that could potentially be used clinically as an anti-inflammatory therapy for the treatment of several lung diseases.Key Words: lung inflammation, pMDI, pressurised metered dose inhaler, simvastatin  相似文献   
112.
Cinobufotalin (CB), one of the bufadienolides prepared from toad venom, was investigated for its cytotoxicity, and the underneath mechanism involved. We primarily utilized DNA fragmentation assay and microscopic observation to assess the effect of various doses of CB in human lymphoma U937 cells. Following that, we investigated other parameters involved in cell death mechanism such as reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and apoptotic proteins activation. HeLa cells were concomitantly used to generalize the data observed. Our results show that CB caused significant DNA fragmentation, decrease of MMP, and an increase in the intracellular Ca(2+) ion and ROS production. In addition, CB induced upregulation of Fas protein, proteolytic activation of cytochrome c, caspase-2, -3, -8 and -9 together with the activation of Bid and Bax. Our findings were further validated using either Fas/FasL antagonist or pan-caspase inhibitor to significantly inhibit CB-induced DNA fragmentation. In our study, we suggest that CB induces caspase dependent cell death in U937 cells, and that Fas plays a role in CB-induced apoptosis. Altogether, our data provides novel insights of the mechanism of action of CB and its potential as a future chemotherapeutic agent.  相似文献   
113.
114.
Selenium (Se) is a naturally occurring trace element that is essential for animal and human nutrition, but the range between dietary requirements and toxic levels is relatively narrow. In this review, we are interested in the beneficial effects of selenium and we report on a number of studies of the selenium status of different populations in Saudi Arabia. The Status reflects the geographical area inhabited by the populations. Apart from the few available studies reviewed here, no data on the human status of Se in Saudi Arabia has been obtained. A further objective of this paper is throw some the light on the direction of future studies.  相似文献   
115.
Hydrazone is a bioactive pharmacophore that can be used to design antitumor agents. We synthesised a series of hydrazones (compounds 4–24) incorporating a 4-methylsulfonylbenzene scaffold and analysed their potential antitumor activity. Compounds 6, 9, 16, and 20 had the most antitumor activity with a positive cytotoxic effect (PCE) of 52/59, 27/59, 59/59, and 59/59, respectively, while compounds 5, 10, 14, 15, 18, and 19 had a moderate antitumor activity with a PCE of 11/59–14/59. Compound 20 was the most active and had a mean 50% cell growth inhibition (GI50) of 0.26 µM. Compounds 9 and 20 showed the highest inhibitory activity against COX-2, with a half-maximal inhibitory concentration (IC50) of 2.97 and 6.94 μM, respectively. Compounds 16 and 20 significantly inhibited EGFR (IC50 = 0.2 and 0.19 μM, respectively) and HER2 (IC50 = 0.13 and 0.07 μM, respectively). Molecular docking studies of derivatives 9, 16, and 20 into the binding sites of COX-2, EGFR, and HER2 were carried out to explore the interaction mode and the structural requirements for antitumor activity.  相似文献   
116.
Obesity is well known to be a contributory risk factor for several disease states, including diabetes mellitus. Further, obese women are more prone to have babies born with congenital abnormalities. Paucity of data on maternal-fetal disposition of essential trace elements in obese pregnancies prompted us to undertake this study. Maternal venous and umbilical arterial and venous samples were collected from obese patients (body mass index >30) and control pregnant women (body mass index <25) at time of spontaneous delivery or cesarean sections and concentrations of essential trace elements such as Cu, Fe, Mo, Se, and Zn determined in various samples by atomic absorption spectrophotometry. Activities of antioxidant enzymes, superoxide dismutase, glutathione peroxidase, and total antioxidant activity in maternal and umbilical blood were assessed using appropriate reagent kits. Maternal-fetal disposition and exchange parameters of elements studied were assessed using established critieria. Concentrations of Cu, Fe, Mo, Se, and Zn in the serum of control pregnant women at time of delivery averaged 2232.6, 2398.1, 10.9, 108.9, and 661.9 μg/L, respectively, whereas in the obese group, the values of the above elements averaged 2150.3, 2446.8, 12.6, 96.8, and 838.9 μg/L, respectively. Umbilical vein/maternal vein ratios of Cu, Fe, Mo, Se, and Zn in the control group averaged 0.29, 1.93, 1.06, 0.76, and 1.12, respectively, whereas in the obese group, their fetal-maternal ratios averaged 0.32, 2.23, 1.06, 0.78, and 1.53, respectively. The Cu:Zn ratio in the maternal vein of the obese group (3.60±0.20) was significantly lower (Student's t-test; p<0.05) than that of the controls (2.50±0.19); however, Cu:Fe ratio (1.04±0.08 vs 1.02±0.09) was not significantly different (Student's t-test; p>0.05) in the two groups. Varying differences were noted in the case of antioxidant enzyme activities between the control and study groups. We conclude that obesity is associated with alterations in maternal-fetal disposition of some essential trace elements and antioxidant enzyme status and that these alterations could pose a potential health risk for the mother as well as the fetus.  相似文献   
117.
Flexible representations of dynamics are used in object manipulation   总被引:1,自引:0,他引:1  
To manipulate an object skillfully, the brain must learn its dynamics, specifying the mapping between applied force and motion. A fundamental issue in sensorimotor control is whether such dynamics are represented in an extrinsic frame of reference tied to the object or an intrinsic frame of reference linked to the arm. Although previous studies have suggested that objects are represented in arm-centered coordinates [1-6], all of these studies have used objects with unusual and complex dynamics. Thus, it is not known how objects with natural dynamics are represented. Here we show that objects with simple (or familiar) dynamics and those with complex (or unfamiliar) dynamics are represented in object- and arm-centered coordinates, respectively. We also show that objects with simple dynamics are represented with an intermediate coordinate frame when vision of the object is removed. These results indicate that object dynamics can be flexibly represented in different coordinate frames by the brain. We suggest that with experience, the representation of the dynamics of a manipulated object may shift from a coordinate frame tied to the arm toward one that is linked to the object. The additional complexity required to represent dynamics in object-centered coordinates would be economical for familiar objects because such a representation allows object use regardless of the orientation of the object in hand.  相似文献   
118.
The main objective of the present study was to improve the quality of pulp and paper industrial wastewater of two local mills RAKTA and El-Ahlia, Alexandria, Egypt, and to bring their pollutant contents to safe discharge levels. Quality improvement was carried out using integrated chemical and biological treatment approaches after their optimization. Chemical treatment (alum, lime, and ferric chloride) was followed by oxidation using hydrogen peroxide and finally biological treatment using activated sludge (90 min for RAKTA and 60 min for El-Ahlia effluents). Chemical coagulation produced low-quality effluents, while pH adjustment during coagulation treatment did not enhance the quality of the effluents. Maximum removal of the tested pollutants was achieved using the integrated treatment and the pollutants recorded residual concentrations (RCs) of 34.67, 17.33, 0.13, and 0.43 mg/l and 15.0, 11.0, 0.0, and 0.13 mg/l for chemical oxygen demand (COD), biochemical oxygen demand (BOD5), tannin and lignin, and silica in RAKTA and El-Ahlia effluents, respectively, all of which were below their maximum permissible limits (MPLs) for the safe discharge into water courses. Specific oxygen uptake rate (SOUR) and sludge volume index (SVI) values reflect good conditions and healthy activated sludge. Based on the previous results, optimized conditions were applied as bench scale on the raw effluents of RAKTA and El-Ahlia via the batch chemical and the biological treatment sequences proposed. For RAKTA effluents, the sequence was as follows: (1) coagulation with 375 mg/l FeCl3, (2) oxidation with 50 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial concentration and 90 min hydraulic retention time (HRT), while for El-Ahlia raw effluents, the sequence was (1) coagulation with 250 mg/l FeCl3, (2) oxidation with 45 mg/l hydrogen peroxide, and (3) biological treatment using activated sludge with 2,000 mg/l initial concentration and 60 min HRT. In conclusion, results confirmed that the application of the proposed sequential treatments removed almost all COD, BOD5, high molecular weight compounds, and silica from RAKTA and El-Ahlia influents and produced high-quality effluents, thus achieving the main objective of this study.  相似文献   
119.

Purpose

Identifying among nephroblastoma those with a high propensity for distant metastases using cell cycle markers: cyclin E as a regulator of progression through the cell cycle and Ki-67 as a tumor proliferation marker, since both are often deregulated in many human malignancies.

Methodology/Principal Findings

A staining index (SI) was obtained by immunohistochemistry using anti-cyclin E and anti-Ki-67 antibodies in paraffin sections of 54 postchemotherapy nephroblastoma including 42 nephroblastoma without metastasis and 12 with metastases. Median cyclin E and Ki-67 SI were 46% and 33% in blastemal cells, 30% and 10% in stromal cells, 37% and 29.5% in epithelial cells. The highest values were found for anaplastic nephroblastoma. A correlation between cyclin E and Ki-67 SI was found for the blastemal component and for the epithelial component. Univariate analysis showed prognostic significance for metastases with cyclin E SI in stromal cells, epithelial cells and blastemal cells (p = 0.03, p = 0.01 and p = 0.002, respectively) as well as with Ki-67 SI in blastema (p<10−4). The most striking data were that both cyclin E SI and blastemal Ki-67 SI discriminated between patients with metastases and patients without metastasis among intermediate-risk nephroblastoma.

Conclusions

Our findings show that a high cyclin E SI in all components of nephroblastoma is correlated with tumor aggressiveness and metastases, and that assessment of its expression may have prognostic value in the categorization of nephroblastoma.  相似文献   
120.
In this paper, a simple and highly sensitive spectrofluorimetric method was developed and validated for the determination of entacapone (ETC). The proposed method is based on forming a highly fluorescent product through the reduction of ETC with Zn/HCl. The produced fluorophore exhibits strong fluorescence at λem 345 nm after excitation at λex 240 nm. The use of fluorescence enhancers such as Tween‐80 and carboxy methyl cellulose (CMC) greatly enhanced the fluorescence of the produced fluorophore by 150% and 200%, respectively. Calibration curves showed good linear regression (r2 > 0.9998) within test ranges of 0.05–2.0 and 0.02–1.80 μg mL?1 with lower detection limits of 1.27 × 10?2 and 4.8 × 10?3 μg mL?1 and lower quantification limits of 4.21 × 10?2 and 1.61 × 10?2 μg mL?1 upon using Tween‐80 and or CMC, respectively. The method was successfully applied to the analysis of ETC in its pharmaceutical formulations (either alone or in presence of other co‐formulated drugs). The results were in good agreement with those obtained using the official method. The methods were further extended to determine the drug in human plasma samples, and to study the pharmacokinetics of ETC. The paper is the first report on the spectrofluorimetric determination of entacapone.  相似文献   
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