Khaled A. Osman

Oxidative Stress and Pharmacokinetics of Pendimethalin in Female Rats

The propensity of a dinitroaniline pre-emergence herbicide, pendimethalin, to induce oxidative stress, changes in biochemical parameters, pharmacokinetics, tissue distribution and excretion in serum, kidney, liver and brain of female rats following four oral doses of 109.4 mg/kg b.wt every other day were studied. When rats exposed to pendimethalin, significant increases in tissue malondialdehyde, lactic dehydrogenase and alkaline phosphatase levels (p<0.05) were noticed compared to controls. The activities of catalase in all the tested tissues except brain were significantly increased (p<0.05) after pendimethalin treatment. Pharmacokinetic studies illustrated that when rats were treated with a single dose of 109.4 mg/kg b.wt of pendimethalin, the percentages of pendimethalin excretion in the urine and faeces were 8.72 and 14.31 after 24 which increased to 23.81 and 71.21 after 168 h of administration. The Peak concentrations of pendimethalin were reached at 12 h in serum (3229.14 ng/mL), liver (10162.32 ng/g) and kidneys (1969.17 ng/g), whereas the peak concentration (245.92 ng/g) reached at 24 h after dosing. In all the tested tissues the compound declined in all tissues as time passed after 72 h in serum or after 120 h in liver, kidneys and brain following administration. The disappearance of pendimethalin was found to be biexponentially from the tested tissues with half-life) t½ (of 14.0, 15.0, 2.5, and 29.0 h for the serum, liver, brain and kidneys, respectively. It can be concluded that when female rats are exposed to pendimethalin, it is readily absorbed and subsequently distributed throughout the whole body influencing on the biomarkers oxidative stress and enzyme activities.

Pesticides-induced oxidative damage: Possible in vitro protection by antioxidants

To determine if quinine has a metabolic effect during treatment of severe or complicated malaria, we studied its effects on plasma glucose and plasma insulin levels in 150 pregnant women with malaria referred to Madani maternity teaching hospital, Gezira state and 50 healthy pregnant controls. Levels were determined at baseline (day 0) before the start of quinine treatment, after 2 days of treatment (2 hours after the 4th dose) and after 7 days of treatment (day 8). There was a statistically significant increase in plasma insulin concentrations during the quinine infusion and fall in plasma glucose concentration (P < 0.001). Quinine administered at the recommended dose and rate can disrupt plasma glucose homeostasis although it is still the drug of choice for severe and complicated malaria in Sudan.S health status (SHS) is characterized by ambiguous health complaints, general weakness, and lack of vitality, and it has become a new public health challenge in China and worldwide. SHS is believed to be a subclinical, reversible stage of chronic disease. As studies of intervention and prognosis for SHS are expected to become increasingly important, a reliable and valid instrument for its assessment is essential. A questionnaire for measuring SHS in urban Chinese was developed based on focus group discussions and a literature review. Questionnaire validity and reliability were evaluated in a small pilot study and then in a cross-sectional study of 3000 individuals. The analyses included tests for reliability and internal consistency, exploratory and confirmatory factor analysis, and tests for discriminative ability and convergent validity. The final questionnaire incorporated 25 items on SHS (SHSQ-25), and encompassed 5 subscales: fatigue, cardiovascular system, digestive tract, immune system, and mental status. The SHSQ-25 has proved to be a reliable and valid instrument for measuring sub-health status in urban Chinese. The progress of a combined genomics and glycomics study for exploring the mechanism of SHS and an example of screening novel biomarkers for metabolic syndrome by profiling human plasma N-glycans will be presented.T interactions of membrane receptors during cell adhesion play pivotal roles in tissue morphogenesis during development. Our lab focuses on developing multi-scale models to decompose the mechanical and chemical complexity in cell adhesion. Recent experimental evidences show that clustering is a generic process for cell adhesive receptors. However, the physical basis of such receptor clustering is not understood. We introduced the effect of molecular flexibility to evaluate the dynamics of receptors. By delivering new theory to quantify the changes of binding free energy in different cellular environments, we revealed that restriction of molecular flexibility upon binding of membrane receptors from apposing cell surfaces (trans) causes large entropy loss, which dramatically increases their lateral interactions (cis). This provides a new molecular mechanism to initialize receptor clustering on the cell-cell interface. By using the subcellular simulations, we further found that clustering is a cooperative process requiring both trans and cis interactions. The detailed binding constants during these processes are calculated and compared with experimental data from our collaborator’s lab.P malnutrition is common in patients requiring liver transplantation (LT). However, their nutritional parameters characteristics remain unclear.We examined various nutritional parameters upon admission in 226 consecutive adult patients who underwent LTbetween February 2008 and August 2012;correlations with Child-Pugh (CP) classification, original disease, skeletal muscle mass (SMM) and zinc (Zn) levels.CP-A patients had higher Zn, prealbumin (PA) and branched-chain amino acids (BCAAs)-to-tyrosine (TYR) ratio (BTR) than those with CP-B or CP-C. When patients were grouped whether or not they received BCAAs before admission, TYR levels were higher among those with CP-C than with CP-A/B (P=0.025) who did not receive BCAAs, but did not differ in those administered with BCAAs. BTR was lower in patients with CP-C than with CP-A/B in both groups (P=0.001 and P=0.010, respectively), whereas BCAAs did not differ between patients with CP-A/B and CP-C in either group.SMM correlated positively with TYR (r=0.435, P<0.001) and BCAAs (r=0.193, P=0.029) but negatively with BTR (r=0.272, P=0.002). Zn correlated positively with PA (r=0.457,P<0.001) and BTR (r=0.261,P<0.001) but negatively with ammonia (r=-0.172,P=0.014) and TYR (r=-0.197,P=0.005).Acute liver failure patients had the highest ammonia, Zn, TYR, lowest BTRwith relatively low BCAAs and high PA while alcoholic cirrhosis patients had the highest BCAAs and TYR mean levels. Hepatocellular carcinoma patients had higher BCAAs than cholestatic diseases patients who had the lowest BCAAs and Zn mean levels. Pre-transplant disease, SMM and Zn play important roles in amino acid metabolism and nutrition.Evaluation of said parameters is recommended to tailor peri-LT nutritional regimens.Methods: Hep2 was cultured with medium containing ethidium bromide (EB) to get ρ0 cells, and then PCR, confocal microscope, transmission electron microscopy and growth defect experiment were used to identify the cell model. Afterwards, the radiosensitivity of ρ0 and Hep2 cells were examined by colony formation assay. After radiation, cell proliferation was detected by CCK8 kit, cell cycle and apoptosis were analyzed by flow cytometry, ATP was detected by kit and reactive oxygen species (ROS) content was evaluated by Dichloro-Fluorescein diacetate salt (DCFH-DA) staining method.Wastewater contaminated soil poses serious environmental and health problems in Saudi Arabia and requires technological solutions for mitigating potential environmental risks. In spite the efforts of the Agriculture Ministry and agencies of water resources to overcome those problems, they still exist. In this concern, the effects of an arbuscular mycorrhizal (AM) fungus (Glomus deserticola Trappe and John) on growth, relative chlorophyll content and some mineral nutrients and heavy metal contents of broad bean (Vicia faba) plants grown in sterilized soil irrigated with different concentrations of wastewater were studied. Application of wastewater significantly reduced growth, chlorophyll content, nutrient contents, and levels of mycorrhizal colonization of bean plants comparing to control untreated plants, mainly at high concentrations. However, the rate of reduction was more pronounced in nonmycorrhizal treated plants. Mycorrhizal broad bean plants had significantly higher biomass, plant heights, leaf area, nutrients content (N, P, K), and relative chlorophyll content compared to those of non-mycorrhizal plants irrigated with or without sewage water. Under sewage water application, the AM colonization had greatly reduced the heavy metal contents (Zn, Co, Mn, Cu) in shoot and root tissues of the broad bean plants as compared to their equivalent non-mycorrhizal plants. This study indicates that growing broad bean plants with AM inoculum can minimize the heavy metals toxicity and increase growth and P uptake. In this regard, the AM fungi have a protective role to the host plants, and thus play important roles in soil contaminant immobilization processes. Therefore, the AM fungi are important in phytoremediation of heavy metals in wastewater contaminated soil.

Remediation of lead and cadmium-contaminated soils

ABSTRACT The research was designated to study the ability of plants to bio-accumulate, translocate and remove the heavy metals, lead and cadmium from contaminated soil. The herbal plant ryegrass, Lolium multiflorum was investigated as a bio-accumulator plant for these metals. The translocation of these heavy metals in the herbal plant was compared considering root to shoot transport and redistribution of metals in the root and shoot system. The trace metal contents from root and shoot parts were determined using atomic absorption spectrometer. The results showed that the percent of lead and cadmium transferred to ryegrass plant were averaged as 51.39, and 74.57%, respectively, while those remained in the soil were averaged as 48.61 and 25.43% following 60 days of treatment. The soil-plant transfer index in root and shoot system of ryegrass was found to be 0.32 and 0.20 for lead, and 0.50 and 0.25 for cadmium. These findings indicated that the herbal plant ryegrass, Lolium multiflorum is a good accumulator for cadmium than lead. The soil-plant transfer factor (the conc. of heavy metal in plant to the conc. in soil) indicated that the mechanism of soil remedy using the investigated plant is phytoextraction where the amounts of heavy metals transferred by plant roots into the above ground portions were higher than that remained in the soil. The method offers green technology solution for the contamination problem since it is effective technology with minimal impact on the environment and can be easily used for soil remedy.