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Isolation of antimicrobial peptides from Apis florae
No full textAs part of the ongoing search for novel antimicrobial agents and their use in singular or
combined drug therapy, peptide fractions of molecular weights about 14.500 and 15.00 kDa were
isolated from the hemolymph of wild (Apis florae) and carniolan (Apis carnica) bees of Saudi Arabia
obtained from different regions in Riyadh (variable plant sources) during the honey seasons (spring
and summer) 2008–2009. Following experimental infection with 1.1 • l06 viable Escherichia coli cells
(ATCC 25922), the antimicrobial peptides were purified to homogeneity by reversed-phase high
performance liquid chromatography. Antibacterial activity of the isolated peptide was evaluated
in vitro by an agar well diffusion method for E. coli strain (ATCC 25922) and Klebsiella pneumoniae
strain (ATCC 11678), the major Gram negative pathogens causing urinary tract infections, and
Staphylococcus aureus (ATCC 6538) as Gram positive bacteria. A total of 10 honey samples collected
from bee hives selected arbitrary at different floral areas of south Riyadh were also investigated
for their antimicrobial activities against the yeast, Candida albicans (ATCC 10231) and four
standard bacteria strains, E. coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), S. aureus
(ATCC 6538) and Bacillus subtilis (ATCC 6633) using standard antimicrobial assays. The isolated
antibacterial peptides and the different honey samples revealed comparable marked variations in
antimicrobial activities and their sensitivity might be depending on their variable floral sources.
ھ 2011 King Saud University. Production and hosting by Elsevier B.V. All rights reserved.Research
Centre of Female Sections for Science and Medical
Studies King Saud University, and King Abdul Aziz City for
Science and Technolog
Impact of heavy metal pollution on the hemogram and serum biochemistry of the libyan jird, Meriones libycus
No full textThe stress profiles of the hemogram and serum biochemistry were determined in the context of heavy metal (Cd, Cu, Hg, Ni and Pb) exposure in the wild libyan jird, Meriones libycus, from one of Riyadh’s polluted areas versus a reference site. Coupling the pronounced drop in platelets (PLT) (28%) and mean platelet volume (MPV) (17%) with the insignificant responses of other red blood cell indices, suggests bone marrow suppression that is characterized by thrombocytopenia as an initial abnormality. The speciesspecific stress leukogram for M. libycus is expressed by leukocytosis (66%), monocytosis (40%), lymphocytosis (23%) with eosinopenia (81%) and neutropenia (42%). Hyperglycemia (50%), hyper-lowdensity-lipoproteinemia (38%), hypocortisolism (85%) and hypotriglyceridemia (55%) depicted serum biochemistry profile. In polluted jirds, the elevated activities of pseudocholinesterase (PChE) and serum marker enzymes (alanine aminotransferase ALT, aspartate aminotransferase AST and creatine kinase CK) strongly suggest functional damage of the liver and/or heart. A potential role of PChE in low-density lipoprotein (LDL) metabolism is implied in the joint rise of both indices and in the recognized relationship between PChE and lipid metabolites. While increased utilization in lipid metabolism and energy synthesis could rationalize the inhibition of the normal patterns of triglycerides and lactate dehydrogenase (LDH), the inhibited activities of LDH could additionally be attributed to its hormetic behavior towards low and high metal concentrations. The overall findings presented here documented the relevance of M. libycus in biomonitoring and predicting the risk imposed on human populations living in polluted areas.Chemospher
Circulating ghrelin levels and the polycystic ovary syndrome: correlation with the clinical, hormonal and metabolic features
No full textObjectives: Dysregulation of ghrelin levels may lead to physiological problems including obesity and Polycystic Ovary Syndrome (PCOS). The aim of the study was to compare ghrelin levels in women having PCOS. Study Design: Serum ghrelin levels (pre and postprandial) were compared between 30 Saudi women suffering from PCOS and 30 healthy controls. The relationship between circulating ghrelin levels and biochemical manifestation of other hormones were investigated. Anthropometric were measured for all the subjects. Biochemical and hormonal investigations included, plasma glucose, insulin, leutinizing hormone (LH), follicular stimulating hormone (FSH), 17β-estradiol (E2), progesterone, testosterone and sex hormone binding globulin (SHGB) and serum ghrelin levels. The data was statistically analyzed using independent T-test and ANOVA. Correlation studies were performed between ghrelin levels and other variables.Results: No differences were observed in the levels of ghrelin during fasting and post prandial period in the PCOS (p=0.487) and control groups (p=0.378). Significant inverse correlation was observed in ghrelin levels (fasting and postprandial) levels and BMI (PCOS: r=−0.529; p=0.009, controls: r=−0.670; p=0.005); PCOS: r=−0.421; p=0.007, controls: r=−0.491; p=0.004 respectively). No correlations between ghrelin levels and other parameters were observed. Conclusion: The findings of the study suggests that circulating plasma ghrelin levels were found to be normal and were inversely related to BMI in women with PCOS. No relationship between circulating ghrelin levels and the abnormal hormonal pattern of the PCOS were observed
2D J-resolved (PRESS) NMR amino acids in-vivo measurements and data analysis
No full text2D J-resolved (PRESS) at 1.5 tesla measurements of in vitro and in vivo are presented. Assignments and quantification of resonances of alanine (Ala), γ-amino butyric acid (GABA), glutamate (Glu), glutamine (Gln), creatine (Cr), N-acetyl aspartate (NAA), choline (cho), and Lactate (Lac) are obtained for 12 volunteers. The in vivo spectra of these amino acids were assigned based on the in vitro 2D measurements. The quantification of these amino acids for the in vivo measurements was obtained by calculating the ratio of their concentration to the Cr concentration. The resulted quantification ratio of the measured amino acids was in good agreement with literature [1].King Saud universit
Normative values for one-leg stance balance test in population-based sample of community-dwelling older people.
No full textAbstract: This study aimed to generate normative values for one-leg stance test(OLST) with eyes-opened and eyes-closed conditions across Arabian population by age and gender to serve as an acceptable reference standard. 194 volunteers healthy Saudi community-dwelling elders. aged 60-80 years were recruited from Riyadh. kingdom of Saudi Arabia. their ability to stand balanced on one leg was measured. Results showed that the duration that individuals are able to maintain standing balanced on one leg. Is age-specific and related to gender. There was inverse relation between age and balance with longer time maintained in on limb with eyes-opened than with eyes-closed. Men showed better performance than woman. In conclusion, this study would aid clinicians in understanding the age specific level of performance that is to be expected in healthy community-dwelling elders during OLST examination and provided normative values to which individuals could be compared
Design ,synthesis and Docking Studies of Novel Diarylpyrazoline and Diarylisoxazoline Derivatives of Expected Anti-inflammatory and Analgesic Activites
No full textTwo series of novel non acidic 3, 5-diarylpyrazoline and 3, 5 diarylisoxazoline derivatives were designed to be synthesized and screened for anti-inflammatory and analgesic activities. In addition, molecular modelling and docking of the designed compounds into cyclooxygenase II (COX-II) using Molsoft ICM 3.4-8C program was performed in order to predict the affinity and orientation of the designed compounds at the active site compared with its binding inhibitor celecoxib. The ICM score values show good agreement with predicted binding affinities, where all the designed compounds exhibit ICM score values (range from -88.89 to -70.40) less than celecoxib (-60.71) revealing higher binding affinity with the enzyme. Accordingly, synthesis of the designed compounds via reaction of various propenone derivatives with hydrazine hydrate, phenyl hydrazine or hydroxylamine hydrochlorides were carried out. Evaluation of their activity as anti-inflammatory and analgesics using dextran-induced rat paw edema,
formaldehyde arthritis test and paw pressure test, respectively and their ability to induce gastric toxicity was also estimated. All the synthesized compounds exhibited significant activity as anti-inflammatory and analgesic, where compounds 2 and 8 were the most active as anti-inflammatory in dextran-induced rat paw edema, while compounds7 and 10 were the most active as anti-inflammatory in formaldehyde-induced arthritis rat paw edema test. All compounds showed analgesic activity with the most potent compounds were 3, and 10 were the most active. No one of the tested compounds cause gastric toxicity. We can conclude that the synthesized compounds proved a successful hit and seem potentially attractive as anti-inflammatory and analgesic agents.Cairo universit
ترميم وصيانة مقصورة الكاتب ماعى حفائر كلية الآثار – جامعة القاهرة، سقارة.
No full textيتناول هذا البحث ترميم وصيانة مقصورة الكاتب ماعى حفائر كلية الآثار، طرق فحص وتحليل المواد الأثرية، تشخيص الحالة، خطة العلاج والصيانة
INFLUENCE OF SELF-EMULSIFYING DRUG DELIVERY SYSTEMS ON THE AQUEOUS SOLUBILITY AND DISPERSION OF CINNARIZINE
No full textMastersPurpose:
Oral route is considered to be the most convenient and preferred route for the
patient among various routes of drug delivery systems. However, oral delivery of many
drug compounds is hampered because of the high lipophilicity of the drug itself. Nearly
40% of new drug candidates exhibit poor water solubility which leads to poor oral
bioavailability, high intra- and inter-subject variability and lack of dose proportionality.
To overcome these limitations, different techniques such as using carrier systems
and complexation with cyclodextrins have been used to enhance the solubility of poorly
water-soluble drugs (PWSD) but the enormous cost and complexity of manufacturing
process have limited their commercial viability.
However, formulating PWSD in self-emulsifying and/or self-microemulsifying
drug delivery system (SEDDS/SMEDDS, respectively) offers an attractive alternate.
SEDDS/SMEDDS are oral lipid dosage forms containing mixture of oil, surfactant, drug
and possibly other components which can form a fine emulsion or microemulsion upon
dilution in the aqueous lumen of the gut offering an improvement in the rate and extent of
absorption and more reproducible plasma-concentration profiles. SEDDS/SMEDDS offer
exclusive advantage over conventional formulations in the spontaneous formation with
low energy requirement beside the excellent thermodynamic stability.
Cinnarizine (CN), a highly lipophilic compound with log P = 5.8, was selected as a
model drug for the current thesis. The key objective of the work is to design
SEDDS/SMEDDS capable of presenting and maintaining the drug in solution for
sufficient time to allow for absorption.
Methods:
Initially, an isocratic reverse phase chromatographic method employing ultra
performance liquid chromatography (UPLC) was developed for the quantification of CN
in pure and pharmaceutical formulations. The proposed method was successfully
validated with respect to the standard FDA guidelines.
Mainly, the work involved designing and characterizing SEDDS/SMEDDS
formulations of CN. The designed formulations were initially screened for their selfemulsification
efficiency. Equilibrium phase diagrams were constructed to evaluate phase
changes that can occur at various stages of aqueous dilution. The equilibrium solubility
within anhydrous and diluted formulations was investigated to determine the formulation
solvent capacity and speculate their precipitation tendency, respectively. The droplet size
distribution was measured upon (1:1000) aqueous dilution of SEDDS/SMEDDS
formulations. Dynamic dispersion studies were carried out mainly to assess the
precipitation magnitude upon aqueous dilution of the formulation. Furthermore, in-vitro
dissolution studies were conducted to compare the dissolution profiles of selected
SEDDS/SMEDDS formulations with the marketed Stugeron® tablets.
Finally, the work involved stability assessment of CN within SEDDS/SMEDDS
formulations at accelerated and long-term storage conditions.
Results:
SEDDS/SMEDDS formulations have shown diverse self-emulsification
efficiencies depending on the oil and surfactant components. The best self-emulsification
efficiencies were reported with mixed glycerides and/or hydrophilic surfactants.
Equilibrium phase diagram studies revealed that a minimum of 50% surfactant was
needed to achieve efficient self-emulsification. Increasing the monoglycerides
concentration within the oil component led to enhancing water solubilization thus
enhancing the self-emulsification efficiency. The CN solubility within the anhydrous
formulations showed remarkable variability according to the formulation type and
composition. The CN solubility increased with increasing the lipid chain length and/or
surfactant lipophilicity. Determining the CN solubility within the diluted formulations
revealed that the total mass in solution almost remained the same which suggests no
precipitation tendency. The mean droplet size of the diluted formulations decreased in
case of using mixed glycerides, with decreasing the lipid chain length and/or increasing
surfactant hydrophilicity. In case of dynamic dispersion studies, when the formulation
showed accepted release efficiency, no significant precipitation was detected with all the
formulation types.
In the dissolution studies, all the tested self-emulsifying formulations showed
superior dissolution profiles compared with Stugeron® tablets in both simulated gastric
fluid (SGF) and simulated alkaline fluid (SIF). Upon shifting from SGF to SIF,
Stugeron® showed significant precipitation (leaving only 8-13% CN in solution) while
the self-emulsifying formulations were able to hold more than 74% CN in solution.
All the formulations investigated in the dissolution studies were also included in
the stability assessment studies. The accelerated stability study revealed significant
degradation within all the formulations. On the other hand, the long term stability study
revealed that formulations containing saturated medium chain glycerides were able to
provide good chemical and physical stability up to 6 months.
Conclusion:
Self-emulsifying formulations represent a valuable option to improve the oral
bioavailability of PWSD compounds. However, the selection of components and their
relative quantities in the formulation are very critical and vary from drug to another. The
optimum formulation selection depends mainly on the physico-chemical properties of
each drug. Formulations containing medium chain mixed glycerides showed remarkable
suitability for CN. Regardless of the surfactant type, formulations containing medium
chain mixed glycerides showed enhanced self-emulsifying efficiency, satisfactory CNsolubility,
low droplet size, superior dissolution and better CN-stability profiles.
Accordingly, the choice of lipid (oil) seems to be the most vital step in designing the CN
self-emulsifying formulations
Development of In Situ Gelling Formulations for Per-Oral Sustained Delivery of Dextromethorphan
No full textMastersPurpose:
The aim of our work was to develop a modified in situ gelling oral liquid sustained release formulations of dextromethorphan using alginate based systems. These systems were further reinforced to provide sustained release behavior over different sites of the GIT through:
A. Reinforcing the gel structure through incorporation of another polymer with sodium alginate, namely chitosan.
B. Controlling the solubility of the drug through formation of solid dispersions of DM with Eudragit S 100 in different ratios, before dispersing the resultant microparticles in the alginate vehicle.
Results:
The alginate concentration of 2 % w/v (the most optimized vehicle) showed excellent flow properties and high gelling capacity in the physiological conditions. However, dose dumping is still a problem with all the forumlations.
Alginate/Chitosan in situ gelling systems showed a pseudoplastic flow patterns. The in vitro release investigations revealed that the alginate/chitosan dispersion of concentration (2:1.5 % w/w alginate: chitosan) was found to be the most efficient one with release efficiency 32.76 % after 8 hr.
The interaction studies revealed the occurrence of interaction between DM & Eudragit S 100. The in vitro release behavior of the formulations showed a sustained release effect & similarity with the marketed product.
Conclusion:
Improvement of the gelation & in vitro release characteristics of the alginate/chitosan mixture is possibly not only a result of a combination of two in situ gelling ion responsive polymers, but may also be due to a synergistic interaction between
the two polymers resulting in the formation of a firm gel structure capable of holding the drug for a period of time up to 8 hr.
The sustained release properties have been improved by the combined effect of the in situ gelation behavior of alginate solution & the partial coating of DM microparticles with ES 100 in the formulation
Causes of EFL speaking weakness in Saudi Secondary Schools in Al-Gunfuthah City
No full textThe major aim of this study is to investigate the causes of EFL speaking weakness in Saudi secondary schools in Al-Gunfuthah City. 240 students are selected randomly from four secondary schools in Al-Gunfuthah. 60 students from each school participated in the study. These students were selected randomly from three levels in each secondary school. In addition, 30 English teachers in Al-Gunfuthah city were selected randomly to contribute to the study.
Four instruments are used in this study which are students' questionnaire, teachers' questionnaire, students' interview and teachers' interview.
The most important findings of this study are as follows:
1. Saudi secondary school students are generally weak in speaking English.
2. Most secondary school students have a positive attitudes towards speaking in English.
3. Speaking difficulties faced by the students are related to pronunciation, grammar, vocabulary, and fluency.
4. There are many reasons for students' weakness in terms of speaking in English. These reasons are associated with the English textbook used in the secondary level, the students, and the English teachers.
Based on the findings of this study, the following recommendations can be made:
1. The Ministry of Education should recognize that secondary school students are generally weak with regard to speaking English. Hence, they are responsible for solving this problem and developing spoken English in the secondary schools.
2. The results reveal that most of the students have positive attitudes towards speaking English. So, the English teachers should make use of this factor to improve students' speaking skills by motivating students to speak in English.
3. English class should be divided into four separate parts based on the four skills (speaking – listening – reading – writing), in order to guarantee teaching all of the four skills comprehensively.
4. The use of effective teaching aids such as language laboratories, videos, and computers to teach English.
5. Increasing the number of English contact hours (periods) in order to give the students the enough opportunities to practice English language