Mahmoud Abd El Hafez M. Adam

Granulomata formed in the liver or lung of man and animals infected with schistosomiasis are common manifestation of an inflammatory delayed hypersensitivity reaction. Non-steroidal anti-inflammatory drugs (NSAIDs) (tiaprofenic acid and piroxicam) have been used alone and as adjuvants to praziquantel in treating pulmonary granulomata induced in mice by injecting them intravenously with S. mansoni eggs. The size of the granulomata, as well as some immunological parameters, have been measured at the end of treatment. Both anti-inflammatory drugs effectively reduced the size of lung granulomata in a dose-dependent manner. The immediate skin reaction and, to a lesser extent, the delayed reaction were reduced by these drugs. Tiaprofenic acid, but not piroxicam, reduced the percent macrophage migration inhibition in vitro. The combined therapy of either of the drugs with praziquantel did not result in an additive effect.

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The effect of heat treatment on the structure, transformation and electrical conductivity (σ) of the amorphous alloy of Ge20Se5Te75 is studied. X-ray diffraction experiments on annealed samples, at temperatures higher than the glass transition temperatures, show the appearance of Te and TeGe crystalline phases. On heating the amorphous sample above the glass transition temperature irreversible electrical conductivity changes are observed. The temporal changes in σ-values of Ge20Se5Te75 samples, at different isothermal annealing temperatures, are used to determine the transformation ratios from amorphous to crystalline state, subsequently the kinetic parameters are calculated. It is found that the crystallization is a two dimensional process and a value of 1.02±0.12 eV has been obtained for the activation energy of the crystal growth in the temperature range 230-270°C. © 1988.

The crystallization kinetics of glassy alloy SeGe20, to which small concentrations of foreign elements such as In, Tl, As, Sb and Bi are added, were investigated at temperatures of 75, 85, 95 and 105°C. It is found that the crystallization process of the annealed doped and undoped glassy alloy SeGe20 is one-dimensional. The rate of crystallization depends on the doping element and its concentration. The effect of introducing elements on the crystallization process is discussed. © 1988.

The d.c. conductivity, a.c. conductivity and thermoelectric power of the compounds H3N+(CH2)+ NH3FeCl4, where n=2, 3, 7 and 10, have been studied over a temperature range of 150-500 K. The conductivity results confirm the presence of more than one structural phase transition for each compound investigated. The thermoelectric power measurements showed that electrons are the main charge carriers in all crystal phases. The conductivity results were explained on the basis of an electron hopping mechanism over the whole temperature range. © 1988 Chapman and Hall Ltd.

The electrical conductivity of γ-irradiated and unirradiated finely-divided spinels of composition (Znx2+Fe1-x2+Fe23+)O42-was studied in a nitrogen atmosphere as a function of temperature. The results of both γ-irradiated and unirradiated ferrites with compositions x ≤ 0.79 showed that the electrical conduction occurred by fast electron exchange amongst Fe2+ and Fe3+ ions situated on octahedral sites in the spinel lattice, by a hopping mechanism. For composition x > 0.79 it was found that the transition of the charge carriers through cation vacancies is the predominant mechanism. Some breaks in the conductivity-temperature curves were found near the Curie points. Seebeck voltage measurements showed that γ-irradiated and unirradiated spinels behave as n-type semiconductors. The effect of γ-irradiation on the conductivity, activation energy, charge carriers and the conduction mechanism is discussed. © 1988 Chapman and Hall Ltd.

The electrical conductivity of the compounds (CH2)n(NH3)2FeCl4-xBrx (n = 8, 9 and 10 and (x = 0, 1 and 2) was measured in the temperature range from liquid nitrogen up to near the melting point of the samples. The effects of a gradual replacement of Cl- ions by Br- ions as well as the effect of layer spacing on the electrical conductivity are discussed. The phase transition points are determined and the values of the activation energies for the low (phase I) and high (phase II) temperature phases are calculated and listed. © 1988.

The dielectric constant ε and the pyroelectric current Ip for the compounds (CH2)8(NH3)2FeCl4-xBrx(x=0, 1 and 2) have been measured in the range from the liquid nitrogen temperature up to near the melting points. Measurements of the dielectric constant have been carried out at various frequencies. A calculation of the electric dipole moments at the background and transition points is given. Calorimetric measurements have also been carried out and the values of the enthalpy change ΔH and entropy change ΔS are also reported.

Bacteria other than fecal coliform were isolated from the negative Eijkman test tubes by streaking on eosin methylene blue agar plates. A total of 101 isolates from underground water pumped from three water works in Cairo were classified into genera or groups according to their morphological, cultural and physiological characters and tested for their resistance towards four commonly used antibiotics namely chloramphenicol, tetracycline, neomycin, penicillin and one chemotherapeutic agent namely 2-sulfanilamide pyrimidine. Results showed that 77 and 64 isolates were resistant to penicillin and 2-sulfanilamide pyrimidine and in addition, 32 isolates were resistant to tetracycline. Only 18 and 8 isolates were resistant to chloramphenicol and neomycin, respectively. It was also found that 19 isolates belonging to 6 genera or groups were sensitive towards all of the tested compounds. © 1989.

Based on dipole moment measurements, a study was made of the keto-enol equilibria of five alpha substituted benzoylacetanilide derivatives in two non-polar and one polar solvents at 30°C. The enol mole fractions of the compounds investigated were determined by analysis of their ultraviolet spectra. The same type of study was extended to salicylanilide for its resemblance to the enol tautomer of these compounds. A deduction of the most probable configurations of the keto and enol forms was tentatively made through a comparison between the dipole moments of some suggested configurations for these forms of benzoylacetanilide and those measured in benzene for the alpha methyl benzoylacetanilide and salicylanilide, respectively. These inferred configurations were used to calculate the dipole moments of both tautomers of the other compounds, and consequently, the dipole moment values of their tautomeric mixtures in dioxane and chloroform. A comparison between the dipole moment values of their tautomeric mixtures in dioxane and chloroform. A comparison between the dipole moment values calculated in this way and those measured indicated a solute-solvent interaction with dioxane, which chloroform behaved as a non-interacting solvent. © 1987 Plenum Publishing Corporation.