Volume 17, Issue 5, Spring 2006, Page 1-149

Effect of Folate Analogues on the Activity of Dihydrofolate Reductase and Seedlings, Callus Growth of Nigella Sativa L. Plant.

Sajida A. Abood; Hekmat M. Al-Dulaimee

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 1-13
DOI: 10.33899/rjs.2006.42804

The study included the effect of three compounds of folate analogues, sulfanilamide, trimethoprim and aminopterin on the growth of seedlings and callus of Nigella sativa plant. These compounds were added at concentration of (10-1-10-5) Molar. The average roots length and the rate of germination in seeds, treated with folate analogues before planting, differed with the type of folate analogue and the concentration used.
The fresh weight and the content of protein, DNA and RNA of callus at 15 and 30 days, were inhibited by the folate analogues.
The decrease in folate content and specific activity of dihydrofolate reductase of callus, grown on media containing inhibitors, was similar to the decrease in fresh weight, protein, DNA and RNA contents. Dihydrofolate reductase activity was not effected by the addition of sulfanilamide either to the In vivo or In vitro system.

Presence and Properties of Cytidine Deaminase in Free living Ciliata Tetrahymena pyriformis

Zahra I. Dallal Bashi; Kusai AL-Chalabi; Muna H. Janker

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 14-25
DOI: 10.33899/rjs.2006.42806

The present investigation indicated the presence and properties of cytidine deaminase (EC. activity in the extract of the free living ciliata Tetrahymena pyriformis.
The optimum conditions for the enzyme activity were determined.Maximum enzyme activity was obtained in a reaction mixture of (300)M of Tris-HCl buffer at pH (7.4) containing (3) mM of cytidine as a substrate, (250)g protein as a source of the enzyme, and an incubation period of (12) min. at (35)C.
Under the optimum conditions,the specific activity was found to be(32.24±0.91)M of cytidine deaminated per min per mg protein in the supernatant of Tetrahymena pyriformis extracts.The Results also indicated that cytidine monophosphate (CMP) might be used as alternative substrate for the enzyme under investigation .

Effect of Colocynth Extract on Ileum Contraction in Mice

Sundus M. Hamza; Ismail S. Al-Kakey

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 26-38
DOI: 10.33899/rjs.2006.42809

Isolated ileal strips of mouse were included in this study to investigate the effect of alcoholic extract of colocynth pulp Citrullus colocynthis and its seeds on their smooth muscles. The results showed that ileal smooth muscles of mouse exhibits regular autorhythmic contractions. The strength and maintenance of normal contraction and that induced by acetylcholine and potassium chloride depended mainly on the extracellular calcium, Also addition of calcium chloride to acetylcholine and potassium chloride induced contraction in solution free from calcium led to augmentation and continuation of tonic phase of the contraction.
Alcoholic extract of colocynth pulp inhibited normal contraction in a concentration dependent manner, and free calcium solution completely closed muscle response to alcoholic extract. It was also observed that this extract gradually inhibited acetylcholine induced contraction.
Different concentrations of the alcoholic extract of colocynth seeds had different effects on ileal smooth muscles. The concentrations (0.05-1) mg / ml activated normal contraction, whereas, high concentrations (2-4) mg / ml inhibited it.

Allelopathic Potential of Some Crops and Vegetables Root Exudates on Mixed Farming in Dohuk Governorate/ Iraq

Hassan A. Al-Mezori; Avesta M.Ali

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 39-52
DOI: 10.33899/rjs.2006.42811

This study investigates the effects of root exudates of corn (Zea mays L.), sorghum (Sorghum bicolor subspecies tichnicum), sunflower (Helianthus annuus L.) ,Tomato (Lycoperscum esculentum L.), pepper (Capsicum frutescens L.),and okra (Hibiscus esculentus L.) on the growth of each others when they are planted in the same field at the same time by applying the stair step technique to study the interference among these plants species.
The results of the study revealed that the root exudates of the plants in question can be classified into three distinct groups: the first group reacted positively with the root exudates of the other plants; In other words their growth has been stimulated by the root exudates of other plants.
It has been noticed that the growth of tomato and sorghum plants has been stimulated significantly by the root exudates of okra plant. Also, the growth of both sorghum and pepper plant has been stimulated by the root exudates of sunflower and has reached 34 % for the sorghum plant.
The second group reacted negatively with the root exudates of other plants. In other words the growth of this group has been inhibited by the effects of root exudations. The growth of pepper plant has been significantly reduced by the root exudates of okra and sorghum plants, the reduction rate reached (29%, 37%) respectively. The growth of tomato and okra plants has been reduced by the root exudates of sunflower plant and the reduction has been 43% in dry weight of tomato plant, but it has not been significant in okra’s plant.
The third group has been affected neither positively nor negatively by root exudates of other plant, such as the growth of pepper plant that had not been affected by root exudates of sunflower.

Effect of Pyrimethamine on Rhythmic Spontaneous and Acetylcholine Induced Contraction in the Ileal Smooth Muscle of Albino Mice

Sundus M. Hamza; Ismail S. Al-Kakey

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 53-60
DOI: 10.33899/rjs.2006.42814

Isolated ileal strips of mouse were included in this study to investigate the effect of different concentrations of Pyrimethamine on the contraction of the smooth muscles. The results showed that ileal smooth muscles of mouse exhibits regular autorhythmic contractions. This normal contraction mainly depended on the extracellular calcium in their tension and maintenance .
Pyrimethamine caused a concentration dependent relaxation, and a high concentration (8-14 mM) of it rapidly caused relaxation for a normal contraction. Free calcium solution reduced smooth muscles response to pyrimethamine, The low and moderate concentrations (0.2 and 8) mM led to a partial inhibition of the rhythmic contractions and inhibition of tonic phase of acetylcholine induced contraction.

Suppression of Genotoxic Effects of Cyclophosphamide (CP) and Methotrexate (MTX) in Mice by Cardamom (Elelteria cardamomum) Fruits Extracts

Saad J.Taj-Al-Deen; Mofeed K. Hasan; Esmaeel K. Shubber

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 61-78
DOI: 10.33899/rjs.2006.42815

The present study aimed at investigating the inhibitory effect of cardamom (Elelteria cardamomum) towards the genotoxic effects of two drugs; Cyclophsphamide (CP) and Methotrexate (MTX) in mice. Four cytogenetic parameters were employed to achieve the aim. Those were mitotic index of bone marrow and germ cells, chromosomal aberrations, micronuclei test and sperm head abnormality assay.
Cardamomum fruits were subjected to extraction with two solvents, water and ethanol. From each extracts, four gradually increased doses were evaluated for their toxicity. Doses from plant extracts with no toxic effect was chosen for drug-plant extract interaction was employed in (Balb/c mice). Genotoxicity of CP and MTX were also tested in mice.
Cadamomum extracts showed no toxic effects at doses up to 50 mg/kg which were pictured by cell divisions of bone marrow and germ cells. While both drugs CP and MTX exert genotoxic effects at 100 and 3.25 mg/kg respectively. These plant and drug doses were applied for plant drug, and drug–plant interaction studies.
The result revealed that the aqueous and alcoholic extracts of cardamomum exhibit a good protective activity. This was depicted by increasing the mitotic activity and reducing the chromosomal aberration, micronucleus, and sperm head abnormality-frequencies. The alcoholic extract was more potent in protection activity compared to equalize extract specially when it was proceeding the drug treatment.

Isolation and Characterization of Urease from Local Vicia faba L.

Laylas F. Bedewia; Tareq Y. Ahmad

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 79-91
DOI: 10.33899/rjs.2006.42819

The research was concerned with the isolation of urease form local Vica faba using different biochemical techniques.
It was shown that gel filtration chromatography of the proteinous precipitate which was produced by acetone, heat treatment and acid precipitation gave three proteinous peaks. The first and the second peaks possessed a variable activity of urease where maximum specific activity was obtained in the second peak which showed (40.1) folds of purification.
Furthermore, the comparative molecular weight of the partially purified urease using both sodium dodecyl sulphate-polyacrylamide gel electrophoresis and gel filtration chromatography techniques was found to be (460000 ± 5000)and (480000 ± 8000) dalton respectively .
The optimum conditions of urease was obtained using (50 mM) sodium phosphate buffer at pH (8.3) with incubation temperature (50)ْ C, incubation time (30) minutes and (5 mM) of urea as a substrate. Using Lineweaver-Burk plot, it was found that Vmax and Km had the values of (0.8) unit/ml and (6.06 mM) respectively.
The results were also indicated that the activity of the enzyme decreased gradually to (70%) and (59%) when the enzyme was stored for (30) days at (4)ْC and room temperature respectively. The activity of the enzyme was inhibited by CuCl2 or methyl urea where the inhibition is competitive .
Finally, the results predicted that there was no significant differences between the activity of urease extracted from local Vicia faba and the urease used in the standard kit for the determination of urea in blood for normal and patients.

Stromatolitic Horizons in the Mulussa Formation Western Desert, Iraq

Abdulla S. Dawood; Thamer A. Aghwan

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 92-104
DOI: 10.33899/rjs.2006.42820

Widespread occurrence of stromatolitic horizons is documented in the middle part of Mulussa Formation, of the Gaara depression western of Iraq. These stromatolitic horizons are associated with intertidal channels, fenestral (birdseye) porosity, trace fossils of Rhizocorallium, as well as chert nodules with varnished evaporites.
The main petrographics constituent appeared to be calcite with radial pattern enclosed between dark algal walls, later replacement by dolomite and silica is common.
Based on the sedimentary attributes and characteristic features of these stromatolitic horizons and their comparison with recent and ancient analogous, an intertidal-lagoonal environment is inferred during their deposition.

Application Stream Cipher on Artificial Neural Network

Raya J. Al Etew; Laheeb M. Al zaubaidy

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 105-123
DOI: 10.33899/rjs.2006.42823

This work aims to find the methods that help Cryptanalysis to break one of secret key system, that is stream cipher by used artificial neural network as plain text attack instead of using the old known methods, such as matrix and massy algorithm to break stream cipher.
C++ Language Version (3.0) was used in this study on computer type (Pentium 300 MHZ)

Study the Effect of Gamma-Ray and Annealing on the Optical Absorption of Glass

Sulaiman H. Mohammed; Ahmed K. Mheemeed

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 124-138
DOI: 10.33899/rjs.2006.45077

A study of Gamma-ray effects on the optical absorption of glass for a range of wavelengths ( 300-900 ) nm with doses varied between (0.331-2.65) Mrad. The effect of annealing treatment on the optical absorption within the range of (50-400)C has been also studied, then the calibration line for measuring the irradiation dose for Gamma-ray on the glass was established. Two models were used to measure the activation energy at fixed annealing time (0.25) hr.

The Effect of Gamma Radiation On Electrical Properties For Thin Film Capacitors Of Poly Mathyl Metha Acrylate (PMMA)

Zahraa B. Al-dabbag; Yahya N. Al-Jammal

Rafidain Journal of Science, 2006, Volume 17, Issue 5, Pages 139-149
DOI: 10.33899/rjs.2006.45080

In this work firstly, a parallel plat capacitor with thin film of Poly Mathyl Metha Acrylate (PMMA) have been fabricated for different thickness using a spinner technique. Secondly, the effect of gamma ray radiation on electrical properties of these capacitor have been studied. Electrical characteristic of un-exposured and exposured capacitor to gamma ray for different periods times have been studied. The results show that the breakdown voltage, in general, is decreased an exponentially when the capacitor exposured to a certain time of radiation. while it’s reveal an increasing breakdown voltage with the increasing in irradiation period time. This work is also include the study of the effect of radiation on electrical conductivity. The results show that there is an exponentially decreasing in electrical conductivity as increasing exposured time for gamma ray. Finally, the effect of gamma radiation on the value of capacitance for the fabricated capacitor, have been studied. The results show that there is an increasing in it’s value as increasing in exposured time.