Simultaneous quantification of linezolid, tinidazole, norfloxacin, moxifloxacin, levofloxacin, and gatifloxacin in human plasma for therapeutic drug monitoring and pharmacokinetic studies in human volunteers
Helmy S.A.,Damanhour University
Therapeutic Drug Monitoring | Year: 2013
BACKGROUND:: Linezolid may be administered in combination with norfloxacin, gatifloxacin, levofloxacin, moxifloxacin, and tinidazole for the treatment of various infections, such as urinary and respiratory tract infections, to improve the efficacy of the treatment or to reduce the duration of therapy. Knowledge of the antibiotic plasma concentrations combined with bacterial susceptibility evaluated in terms of minimum inhibitory concentration would optimize treatment efficacy while limiting the risk of dose-related adverse effects and avoiding suboptimal concentrations. METHODS:: A new high-performance liquid chromatography assay method was developed and validated for determination of the above-mentioned drugs in small samples of human plasma. After protein precipitation with acetonitrile:methanol (1:1, vol/vol), satisfactory separation was achieved on a Hypersil BDS C18 column (250 × 4.6 mm, 5 μm) using a mobile phase comprising 20 mM sodium dihydrogen phosphate-2 hydrate (pH = 3.2) and acetonitrile at a ratio of 75:25, vol/vol; the elution was isocratic at ambient temperature with a flow rate of 1.5 mL/min. The ultraviolet detector was set at 260 nm. The validated method was applied to assay real plasma samples used for pharmacokinetic studies and therapeutic drug monitoring of the selected drugs. RESULTS:: The assay method described was found to be rapid, sensitive, reproducible, precise, and accurate. Linearity was demonstrated over the concentration ranges as follows: 0.1-30 μg/mL for linezolid and tinidazole; 0.05-5 μg/mL for norfloxacin; and 0.1-10 μg/mL for moxifloxacin, levofloxacin, and gatifloxacin (mean r = 0.9999, n = 12). The observed within- and between-day assay precisions were within 12.5%, whereas accuracy ranged between 92.0% and 112% for all the analytes. The lower limit of quantification was 0.1 μg/mL for all the analytes except norfloxacin which was 0.05 μg/mL. CONCLUSIONS:: This assay method was valid within a wide range of plasma concentrations and may be proposed as a suitable method for pharmacokinetic studies, therapeutic drug monitoring implementation, and routine clinical applications, especially for some populations of patients who receive a combination of these drugs. Copyright © 2013 by Lippincott Williams & Wilkins.
Ismail A.,Damanhour University |
Takeda S.,Nagoya University |
Nick P.,Karlsruhe Institute of Technology
Journal of Experimental Botany | Year: 2014
Salinity does not only stress plants but also challenges human life and the economy by posing severe constraints upon agriculture. To understand salt adaptation strategies of plants, it is central to extend agricultural production to salt-affected soils. Despite high impact and intensive research, it has been difficult to dissect the plant responses to salt stress and to define the decisive key factors for the outcome of salinity signalling. To connect the rapidly accumulating data from different systems, treatments, and organization levels (whole-plant, cellular, and molecular), and to identify the appropriate correlations among them, a clear conceptual framework is required. Similar to other stress responses, the molecular nature of the signals evoked after the onset of salt stress seems to be general, as with that observed in response to many other stimuli, and should not be considered to confer specificity per se. The focus of the current review is therefore on the temporal patterns of signals conveyed by molecules such as Ca2+, H+, reactive oxygen species, abscisic acid, and jasmonate. We propose that the outcome of the salinity response (adaptation versus cell death) depends on the timing with which these signals appear and disappear. In this context, the oftenneglected non-selective cation channels are relevant. We also propose that constraining a given signal is as important as its induction, as it is the temporal competence of signalling (signal on demand) that confers specificity. © The Author 2014.
El-Gerbed M.S.A.,Damanhour University
Toxicology and Industrial Health | Year: 2014
Deltamethrin is globally used in crop protection and control of malaria and other vector-borne diseases. It has a potent insecticidal activity with an appreciable safety margin. However, a number of studies have demonstrated nephrotoxicity of deltamethrin in mammalian and nonmammalian species. Lycopene, a carotenoid occurring naturally in tomatoes, has attracted considerable attention as an antioxidant. This study was focused on investigating the possible protective effect of coadministration of lycopene on deltamethrin toxicity. In this study, male albino rats were divided into four groups of 10 animals each: group I served as control, which received standard diet; group II received oral administration of deltamethrin (1.28 mg/kg per day) for 30 days; group III received both deltamethrin and lycopene (1 mg/kg per day); group IV received lycopene (1 mg/kg per day). After the experiment, the animals were anesthetized and the cytokine, tumor necrosis factor-α (TNF-α), in the serum was measured; the kidney was taken for histological and ultrastructural studies. Deltamethrin significantly increased the TNF-α. The histopathological examination of kidney showed mild necrotic changes. Ultrastructural changes in renal proximal tubules of deltamethrin-treated group included an increased number and irregular shape of mitochondria with sparse fragmented cristae, serious ultrastructural lesions in renal proximal tubular lining cells, vacuolar degeneration in the epithelial cells, increased number of lysosomes and loss of apical microvilli. In addition, focal segmental thickening and the duplication of glomerular basement membrane and podocyte changes were observed. Histopathological and ultrastructural study showed some protective effect of lycopene on kidney tissues. © The Author(s) 2012.
Sadek K.M.,Damanhour University
Acta Informatica Medica | Year: 2012
Introduction: The present study was conducted to evaluate the antioxidant and immunostimulant effects of The Carica papaya fruit aqueous extract (CPF, Caricaceae) against acrylamide induced oxidative stress and improvement of Immune functions which affected by free radicals liberating acrylamide in rats. Material and methods: Sixty male wistar albino rats (195-230g) were assigned to four groups, (fifteen/ group). The first group used as control group and received normal physiological saline orally daily. The second group was supplemented with acrylamide 0.05% in drinking water. The third group was gastro-gavaged with 250 mg/kg of papaya fruit extract orally on daily basis. The fourth group was supplemented with acrylamide 0.05% in drinking water and gastro-gavaged with 250 mg/kg of papaya fruit extract orally on daily basis. The chosen dose of papaya fruit extract was based on the active pharmacological dose range obtained from the orientation study earlier conducted. The experimental period was extended to forty day. At the expiration of the experimental period and night fasting, blood samples were collected from the orbital venous sinus. The sera were separated and used for determining of IgG and IgM and the stomach, liver and kidney homogenates for estimation of MDA, GSH level, SOD and CAT activity as a biomarker of lipid peroxidation and antioxidative stress. Results and discussion: The obtained results revealed that, acrylamide caused significant increases in MDA and decrease of GSH level, SOD and CAT activity due to the oxidative stress induced by acrylamide on membrane polyunsaturated fatty acids in rat's stomach, liver and kidney while administration of CPF aqueous extract, was significantly ameliorated the increased levels of MDA and decline of GSH, SOD and CAT activity in the stomach, liver and kidney tissues caused by acrylamide toxicity. Meanwhile, CPF aqueous extract significantly increased immune functions (IgG and IgM) while acrylamide significantly decrease it specially IgG. Thus, this study suggests that acrylamide-induced oxidative stress in rats can be ameliorated by administration of CPF aqueous extract.
Tuorkey M.,Damanhour University
Interventional Medicine and Applied Science | Year: 2014
There is no doubt that diet could effectively improve health and halt cancers. Dietary phytochemical compounds and their derivatives represent a cornucopia of effectively anticancer compounds. This review discusses existing data on the anticancer activities of curcumin, and then offers possible explanations for and mechanisms of its cancer-preventive action. This review also offers insights into the molecular mechanism and targets through which curcumin modulates cell cycle, apoptotic signals, anti-apoptotic proteins, miRNAs, Wnt/beta-catenin signaling, protein kinases, nuclear factor-κB, proteasome activation, epigenetic regulation including DNA methylation and histone modification. Finally, this review provides explanations for how curcumin reverses the multi-drug resistance (MDR) of cancer cells. © 2014 Akadémiai Kiadó, Budapest.
Sadek K.M.,Damanhour University
Andrologia | Year: 2014
Summary: This study was conducted to determine the mechanism underlying the chemotherapeutic efficacy of an ethanolic Moringa oleifera leaf extract (MOLEE) against chromium-induced impairments of rat testes using biochemical methods. Twenty male Wistar rats were divided into four groups of five animals each. Group I (control), group II injected potassium dichromate (8 mg kg-1) i.p., group III gastrogavaged MOLEE (500 mg kg-1) p.o. and group IV received (potassium dichromate plus MOLEE) by the same doses for 60 days. After the blood samples were collected, the animals were sacrificed to determine the testicular antioxidant status and sperm parameters. The chromium-treated group exhibited a significant decrease in testicular antioxidant enzymatic activities, local immunity and sperm parameters as well as an increase in inflammatory markers when compared with the control and MOLEE-treated group. However, concurrent administration of chromium and MOLEE significantly ameliorated the chromium effects on the sperm parameters, local immunity, inflammatory markers and antioxidant enzymatic activities compared with rats exposed to chromium alone. This study concludes that chronic exposure to chromium produces clear testicular toxicity, which can either be prevented or at least decreased by concomitant administration of MOLEE. Interestingly, the metal ion chelation could attribute partly the antioxidant activities of MOLEE. © 2013 Blackwell Verlag GmbH.
Abou-Shaara H.F.,Damanhour University
Acarina | Year: 2014
Varroa mite (Varroa destructor) is the major challenge for beekeeping worldwide. Therefore, various methods and materials for Varroa control have been suggested and tested including; plant extracts, essential oils, biological agents, mechanical methods and some chemicals. This paper aims to present the available options for Varroa control and to survey the performed comparative studies among these options. This paper can be considered as a good guide for researchers during their studies on Varroa control. The presented review highlights that still more comparative studies among Varroa control options under different ecological conditions are strongly required. Basically the performed researches have been concentrated on testing chemical materials and essential oils while relatively few studies have been done on the other control options. It is concluded that the Varroa mite should be continuously (monthly) managed within honey bee colonies using mechanical methods or treatment with essential oils (mainly thymol). In severe cases, and especially during the fall and not during honey seasons, the use of chemical materials can be done with preference to oxalic or formic acid. © 2014 KMK Scientific Press. All rights reserved.
Darwish M.A.,Damanhour University
Computers and Mathematics with Applications | Year: 2011
We present an existence theorem for monotonic solutions of a perturbed quadratic fractional integral equation in C[0,1]. Our equation contains the famous Chandrasekhar integral equation as a special case. The concept of the measure of noncompactness related to monotonicity, introduced by J. Bana and L. Olszowy, and a fixed point theorem due to Darbo are the main tools in carrying out our proof. Moreover, we give an example for indicating the natural realizations of our abstract result presented in this paper. © 2010 Elsevier Ltd. All rights reserved.
El-Far A.H.,Damanhour University
Current Drug Discovery Technologies | Year: 2015
Medicinal plants are known for their many advantages, including the ability to treat diseases such as cancer. Nigella sativa and its active constituent thymoquinone (TQ) have long been used in traditional medicine for treating various conditions related to the respiratory and gastrointestinal systems as well as breast, colorectal, gastric, hepatic, pancreatic cancers and leukemia. TQ has been documented to possess chemo-preventive and chemotherapeutic antitumor effects. Studies reported that TQ inhibits the growth of cancer cells in animal models and culture tumors. This review summarizes the in vitro and in vivo possible mechanisms of TQ anticancer effect. © 2015 Bentham Science Publishers.
Tuorkey M.J.,Damanhour University
Endocrine, metabolic & immune disorders drug targets | Year: 2013
Diabetes is now one of the most common un-communicable diseases worldwide. Few studies have dealt specifically with the potential therapeutic effect of TNF-α suppressor to decrease oxidative stress markers in patients with diabetes. The aim of this study was to investigate the potential therapeutic and toxic effect of the direct injection of the anti-TNF-α on oxidative stress mediators, proinflammatory cytokines and vascular risk factors associated with diabetes on diabetic rats. Methods: diabetes was induced by streptozotocin, three weeks after the - induction of diabetes, a polyclonal anti-mouse/rat TNF-α rabbit serum was injected in the treated group and sacrificed after 4 weeks. The expression of TNF-α mRNA was measured by RT-PCR. The levels of TNF-α, VEGF, IL-2, IL- 6, HSP-70, troponin-t, 8-OHdG, ICAM-1 and VCAM-1 were evaluated using ELISA. Myeloperoxiase (MPO) and total peroxides (TPs) levels were estimated by biochemical reactions. Results: the treatment of diabetic rats with the anti-TNF-α caused a significant decrease in the TNF-α mRNA expression, which were paralleled with the decreased levels of TNF-α, IL-6, MOP, HSP-70, ICAM-1, VCAM-1, troponin-t and 8-OHdG in the blood serum. On the contrary, all were highly expressed in the diabetic group that may be the leading reasons for the DNA damage and cell loss. Data revealed that TNF-α, HSP-70, IL-6, MPO and adhesion molecules when expressed in diabetic rats, collectively induce dramatic changes. Conclusion: these new findings suggested that targeting TNF-α could effectively reduce expressions of MCP-1, HSP-70, troponin-t, 8-OHdG and VCAM- 1, along with prominent reduction in MPO and IL-6 levels.