SAID SHEHATA

Fifty-one patients with CCT verified cerebral infarction were submitted to serum and CSF radioimmunoassay of FSH, LH, estradiol (E2), progesterone, testosterone, cortisol and T4. The results were compared to those of 82 matched controls. Our findings suggest that (1) high serum E2 is a risk factor of stroke in males; (2) low serum T4 is a risk factor in males; (3) serum testosterone is reduced in acute stroke in males confirming that it is stress sensitive; (4) serum LH was higher in hypertensive thrombotic males when compared to normotensive ones, and (5) FSH, LH, E2 and T4 are undetectable in CSF of patients and controls.

The influence of the prenatal and postnatal maternal environment on stroke susceptibility was evaluated by reciprocally crossing the spontaneously hypertensive (SHR) and the Dahl salt-sensitive (SS/Jr) inbred rat strains to produce reciprocal F1 hybrids that were nurtured, respectively, during prenatal and postnatal life by SHR or SS/Jr mothers. Following placement on a high-salt diet containing 8% NaCl at 35 days of age, F1 rats reared by SHR mothers had shorter survival times and were more likely to die with cerebral hemorrhage than F1s reared by SS/Jrs. Across reciprocal F1 female groups, enhanced susceptibility to stroke was associated with greater elevations of systolic blood pressure, but this association was not seen across reciprocal F1 male groups. There was also an association between blood pressure and stroke within each F1/gender subgroup: Rats eventually suffering strokes developed higher blood pressure after placement on the high-salt diet than rats that did not suffer stroke. Lower day 35 body weights (before exposure to the high-salt diet) were associated with greater likelihood of stroke both across the reciprocal F1 groups, and within three of the four F1/gender subgroups. The differences in stroke susceptibility between the reciprocal F1 groupings may be due to systematic differences in the prenatal and/or postnatal environments of SHR and SS/Jr mothers and may be mediated by variations in the nutritive capacity of the two inbred mothers.

Five clinically health goats were injected with sulfadimethoxine and sulfadimethyloxazole in a single dose of 100 mg/kg b. wt. by intravenous route. Highest concentration levels of sulfadimethoxine and sulfadimethyloxazole in rumen were detected 1 hour following intravenous injection, then the concentration for both compounds declined at 12 and 8 hours post administration, respectively. In addition, both types of sulfonamide completely disappeared in ruminal fluid samples taken after 24 and 12 hours, respectively. The rate of acetylation for sulfadimethoxine and sulfadimethyloxazole were nearly similar and occurred to a high extent in ruminal fluid (22.95 and 23.72%, respectively). On the other hand, both tested drugs increased significantly the ruminal gas production from the first to eight hours after i.v. injection in goats. Changes in the serum enzyme activities (SGOT, SGPT and alkaline phosphatase) observed with sulfadimethoxine and sulfadimethyloxazole, and represented by a significant decrease in the activity of SGOT and SGPT level, alkaline phosphatase 4 hours sulfadimethoxine and in GOT/GPT ratio 24 and 48 hours after i.v. injection, respectively. The creatinine clearance was significantly decreased after 4 hours following the i.v. administration of sulfadimethoxine and sulfadimethyloxazole in goats.

A major constraint for expanding biotechnology in developing countries is the tack of appropriate microbial strains and microbial genetic resources. The recently established Microbial Strain Data Network (MSDN) offers the opportunity of, at least partially, llfting these constraints, since even a small institutional culture collection with limited to moderate facilities can act as an active two-way node in the network. We describe the establlshment of a nucleus for culture collection in the biotechnology laboratory, selecting methodologies as compatible as possible with those of the Cairo MIRCEN, and in assembling a database on the collected strains using a format that lends itself to participation in the MSDN.

Cefotaxime was administered to goats intravenously, intramuscularly and subcutaneously to determine blood and urine concentration, kinetic behaviour and bioavailability. Following a single intravenous injection, the blood concentration-time curve indicated a two compartment open model, with an elimination half-life value (t1/2 beta) of 22.38 +/- 0.41 minutes. Both intramuscular and subcutaneous routes showed slower values, that is, 38.64 and 69.58 minutes. The apparent volume of distribution of cefotaxime in goats was less than 1 litre kg-1 and suggested a lower distribution in tissues than in blood. After intramuscular and subcutaneous injections peak plasma cefotaxime concentrations were 77.8 +/- 1.7 and 44.0 +/- 0.8 micrograms ml-1 at 29.6 and 40.4 minutes, respectively. The average bioavailability of cefotaxime given by intramuscular and subcutaneous injection was 1.08 and 1.25 times the intravenous availability, respectively. The cefotaxime concentration remained in urine 24 hours longer after subcutaneous injection than after intramuscular administration.

The disposition phenazone (antipyrine) was used to study the effect of Schistosoma mansoni infection on the activity of drug metabolizing enzymes in mice. Plasma elimination rate constant (Ke), elimination half-life (t1/2e), clearance (CL) and apparent volume of distribution (Vd) were estimated 8 and 12 weeks after infection of mice with 80 S. mansoni cercariae. Liver and kidney function tests were performed simultaneously. Infection increased the levels of glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactic dehydrogenase (LDH), alkaline phosphatase (AP) and total proteins 8 and 12 weeks post infection. At the same time a decrease was recorded in the total cholesterol level. Moreover infection with S. mansoni produced a decrease in phenazone clearance with an increase in the area under the curve (AUC) of the drug 8 and 12 weeks post infection. Elimination half-lives were 57.92 +/- 14.10 and 72.72 +/- 4.14 min 8 and 12 weeks after infection, respectively, compared to 19.29 +/- 3.30 and 26.14 +/- 5.31 min in corresponding controls. No statistically significant change was recorded in the volume of distribution of phenazone in the groups studied. In addition no significant correlation was found between parameters of phenazone disposition and the enzyme levels studied 8 and 12 weeks after infection.

The disposition phenazone (antipyrine) was used to study the effect of Schistosoma mansoni infection on the activity of drug metabolizing enzymes in mice. Plasma elimination rate constant (Ke), elimination half-life (t1/2e), clearance (CL) and apparent volume of distribution (Vd) were estimated 8 and 12 weeks after infection of mice with 80 S. mansoni cercariae. Liver and kidney function tests were performed simultaneously. Infection increased the levels of glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactic dehydrogenase (LDH), alkaline phosphatase (AP) and total proteins 8 and 12 weeks post infection. At the same time a decrease was recorded in the total cholesterol level. Moreover infection with S. mansoni produced a decrease in phenazone clearance with an increase in the area under the curve (AUC) of the drug 8 and 12 weeks post infection. Elimination half-lives were 57.92 +/- 14.10 and 72.72 +/- 4.14 min 8 and 12 weeks after infection, respectively, compared to 19.29 +/- 3.30 and 26.14 +/- 5.31 min in corresponding controls. No statistically significant change was recorded in the volume of distribution of phenazone in the groups studied. In addition no significant correlation was found between parameters of phenazone disposition and the enzyme levels studied 8 and 12 weeks after infection.

The disposition phenazone (antipyrine) was used to study the effect of Schistosoma mansoni infection on the activity of drug metabolizing enzymes in mice. Plasma elimination rate constant (Ke), elimination half-life (t1/2e), clearance (CL) and apparent volume of distribution (Vd) were estimated 8 and 12 weeks after infection of mice with 80 S. mansoni cercariae. Liver and kidney function tests were performed simultaneously. Infection increased the levels of glutamic oxalacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), lactic dehydrogenase (LDH), alkaline phosphatase (AP) and total proteins 8 and 12 weeks post infection. At the same time a decrease was recorded in the total cholesterol level. Moreover infection with S. mansoni produced a decrease in phenazone clearance with an increase in the area under the curve (AUC) of the drug 8 and 12 weeks post infection. Elimination half-lives were 57.92 +/- 14.10 and 72.72 +/- 4.14 min 8 and 12 weeks after infection, respectively, compared to 19.29 +/- 3.30 and 26.14 +/- 5.31 min in corresponding controls. No statistically significant change was recorded in the volume of distribution of phenazone in the groups studied. In addition no significant correlation was found between parameters of phenazone disposition and the enzyme levels studied 8 and 12 weeks after infection.

Using two different agar based double-layer culture assays, 16 bilharzial urinary bladder carcinoma samples were evaluated for the in-vitro effects of 1 hour's exposure to alpha 2 interferon at 3-log concentrations. Ten of these tumor samples were evaluable for drug sensitivity testing. In the liquid top layer dye exclusion assay, 40%, 60%, and 60% of the 10 tested tumor samples were sensitive to alpha 2 interferon 100, 1,000, and 10,000 units/ml respectively, and 25%, 25%, and 63% of 8 tumor cell suspensions were sensitive to the above drug concentrations when the human tumor colony forming assay was performed. Comparing both assays in 24 different drug measurements, there was a 71% concordance rate. All of the 7 discordant measurements were sensitive in the dye exclusion and resistant in the clonogenic assays. Thus, bilharzial bladder cancer cells are relatively sensitive to the in-vitro effect of alpha 2 interferon, especially of higher concentrations, and a phase II clinical trial deserves consideration.

The pharmacokinetics of kitasamycin after intravenous and oral administration in a dose of 300 mg/kg b.wt. was studied in 18 healthy and 18 Salmonella gallinarum naturally infected chickens. The tissue residue of the studied antibiotic was estimated in 36 normal chickens when it was given orally for 7 successive days. Therapeutic level of kitasamycin was achieved after 15 minutes and persisted for 20-22 hours after its oral administration. Higher serum kitasamycin concentrations were recorded in Salmonella gallinarum infected chickens. The elimination half-life of kitasamycin calculated after single intravenous injection was 9.03 hours in diseased chickens corresponding to 3.74 hours in healthy birds. The body clearance was significantly reduced in diseased chickens (23.86 ml/kg/min) when compared to that in normal ones (62.03 ml/kg/min). Kitasamycin treated broilers should not be slaughtered before 3 days from the last dose as it was detected only in bile and caecum at that time but not in edible tissues.

The electrical conductivity of some γ-irradiated and unirradiated metal-zinc ferrites, M0.1Zn0.9Fe2O4 (M ≡ Mn2+, Co2+, Ni2+, Cu2+ or Mg2+), was investigated as a function of temperature. The ferrites investigated showed n-type conduction. The electrical conduction in M0.1Zn0.9Fe2O4 (M ≡ Co2+, Cu2+, Mn2+, or Ni2+, can be explained by a hopping mechanism, whereas the conduction in ZnFe2O4 and Mg0.1Zn0.9Fe2O4 is interpreted on the basis of the transfer of charge carriers through the cation vacancies present in octahedral sites. The effect of γ-irradiation on the conduction process is discussed. © 1990.

The electrical conductivity of benzaldazine and its o-, m- andp-hydroxy substituents has been measured over a temperature range with included their phase transition temperatures. The effect of intermolecular overlapping as well as hydrogen bonding on the conduction mechanism in the low and high temperature regions was studied using IR spectra and conductivity data. The activation energy values obtained showed that all the compounds behaved as semiconducting materials. © 1990.

A total of 68 actinomycete and 63 fungal isolates obtained from various soils were tested for their ability to antagonize different strains of Azospirillum in sterile soil. It was found that between 78 and 87% of the streptomycete and between 75 and 83% of the fungal isolates respectively did not inhibit azospirilla. Numbers of azospirilla in soil were seriously reduced when they interacted with some of the streptomycete and fungal isolates. In soil treated with both azospirilla and either streptomycetes or fungi, the nitrogenase activity ranged from ca 2-210 nmol C2H4g-1h-1. In general, the acetylene reducing activity (ARA) in soils treated with fungi was reduced more seriously than those treated with streptomycetes; the mean ARA reported in the presence of fungi was 23 nmol C2H4g-1 h-1 against 48 in the presence of streptomycetes. The reduction in both azospirilla number and ARA in soil may have reflected the increasing population of antagonists. Highly-significant negative correlations between the diameter of inhibition zones produced by the active Streptomyces and fungal isolates using the agar-disc method were found with both numbers and ARA of most Azospirillum strains in soil. © 1990.