Phosphorus content and growth of fenugreek as affected by cadmium application

Changes in growth and phosphorus content in plants and seeds of fenugreek with increasing cadmium concentration was evaluated. Root length and shoot length ranged from 11.63 to 27.72 and from 9.70 to 54.78 cm, respectively. With the increasing Cd²⁺ concentration there was a significant decrease in root and shoot length, and fresh mass. Various phosphorus fractions of shoot decreased with increasing Cd²⁺ concentration except lipid P and nucleic acid P which increased at 65 and 95 d after sowing and protein P only increased at vegetative stage. In seeds (60 d after flowering) lipid P increased except at 2.5 μg(Cd²⁺) g^?1 (soil) while protein P decreased.     

Reduced vulnerability of the hypertrophied rat heart to oxygen-radical injury

Effects of xanthine--xanthine oxidase produced oxygen radicals were studied in hypertrophied rat hearts in a Langendorff preparation. Heart hypertrophy was produced by banding of the abdominal aorta for 6 weeks. This resulted in a 22% increase in ventricle/body weight ratio compared with that of sham-operated controls. Perfusion with xanthine--xanthine oxidase caused contractile failure and a significant rise in the resting tension. Complete contractile failure in hypertrophied hearts was seen at 25.5 +/- 3.2 min, whereas in control hearts it happened at 14.4 +/- 5.6 min. Contractile failure due to oxygen radicals in both groups was associated with a decline in high energy phosphates, increased lipid peroxidation, and extensive structural damage. Sarcolemma in both groups became permeable to the extracellular tracer lanthanum. As compared with control, in hypertrophied hearts the malondialdehyde content, indicative of lipid peroxidation, was less by 40%; whereas superoxide dismutase, a free radical scavenger, was higher by a similar amount. These data show a greater capacity of the 6-week hypertrophied heart to withstand a free radical induced contractile failure. This delay in oxygen radical effect can be partially explained by the reduced lipid peroxide content and increased superoxide dismutase activity in the hypertrophied hearts.     

Directed isolation of Micromonospora generic cultures on a selective medium with gentamycin

The results of using selective media with gentamicin for directed isolation of Micromonospora are presented. It was shown that the use of the selective media with gentamicin for isolation of actinomycetes from soils of usual humidity levels markedly increased the frequency of Micronomonospora detection. The use of the selective media with gentamicin for plating out silt substrates containing mainly Micromonospora had practically no effect on the increase in the number of the Micromonospora cultures grown. The number of antibiotic-producing Micromonospora isolated on the media with gentamicin was 3 times higher than that on the control media. The use of the selective media with gentamicin provided directed isolation of Micromonospora.     

Metabolism of vitamin A in the heart increases after a myocardial infarction

The supply of vitamin A to the myocardium by storage organs during increased oxidative stress subsequent to myocardial infarction (MI) was examined in hemodynamically assessed rats using compartment analysis of a radio-labeled vitamin A. 3H-Vitamin A was injected into two groups of rats: an MI group and a control group. There were no differences in the plasma or myocardial content of total vitamin A (unlabeled + labeled) between the two groups. However, the proportion of 3H-vitamin A was greater in the myocardium as well as plasma of MI rats. Rats with MI also had significantly lower 3H-vitamin A levels in liver and kidney than sham controls. The greatest difference in vitamin A content was in the concentrations of 3H-labeled storage forms of vitamin A in the liver of MI animals. Activity of bile salt-dependent retinyl ester hydrolase, an enzyme responsible for hydrolyzing vitamin A storage forms, was significantly increased in the liver of MI animals. These data indicate that analysis of plasma concentrations of vitamin A to ascertain links to cardiac conditions may be inappropriate. Specifically, during MI, increased amounts of vitamin A are mobilized from the liver to the heart without changing plasma concentrations. This is facilitated by an increase in the activity of an enzyme that hydrolyzes vitamin A storage forms.     

Reversibility of ultrastructural, contractile function and Ca2+ transport changes in guinea pig hearts after global ischemia

To understand the subcellular basis of contractile failure due to ischemia-reperfusion injury, effects of 20, 60, and 90 min of global ischemia followed by 30 min of reperfusion were examined in isolated guinea pig hearts. Cardiac ultrastructure and function as well as Ca2+ transport abilities of both mitochondrial and microsomal fractions were determined in control, ischemic, and reperfused hearts. Hearts were unable to generate any contractile force after 20 min of ischemia and showed a 75% recovery upon reperfusion. However, there were no significant changes in the subcellular Ca2+ transport in the 20-min ischemic or reperfused hearts. When hearts were made ischemic for 60 and 90 min, the recovery of contractile force on reperfusion was 50 and 7%, respectively. There was a progressive decrease in mitochondrial and microsomal Ca2+ binding and uptake activities after 60 and 90 min of ischemia; these changes were evident at various times of incubation period and at different concentrations of Ca2+. Mitochondrial Ca2+ transport changes were only partially reversible upon reperfusion after 60 and 90 min of ischemia, whereas the microsomal Ca2+ binding, uptake and Ca2+ ATPase activities deteriorated further upon reperfusion of the 90-min ischemic hearts. Ultrastructural changes increased with the duration of the ischemic insult and reperfusion injury was extensive in the 90-min ischemic hearts. These data show that the lack of recovery of contractile function upon reperfusion after a prolonged ischemic insult was accompanied by defects in sarcoplasmic reticulum Ca2+ transporting properties and structural damage.     

Methodological procedures for detecting antibiotic producers among cultures of the family Micromonosporaceae]

Data on intensification of the search for active cultures among Micromonospora are presented. It was shown that the frequency of detecting the antibiotic-producing cultures among Micromonospora under conditions of fermentation on the corn-glucose medium inoculated with agar blocks amounted to 35 per cent. The use of nutrient media of different composition for growing submerged inoculum of Micromonospora demonstrated that the rate of its growth reached maximum on the peastarch medium. The use of this medium for growing submerged seed material for fermentation in the corn-glucose medium increased the frequency of detecting active cultures from 35 to 43.1 per cent. The assay of Micromonospora antibiotic activity twice, i.e. in 96 and 240 hours of the fermentation process increased the frequency of detecting active cultures up to 57.1 per cent and revealing greater variety of antibiotics. Fermentation of Micromonospora cultures simultaneously on 6 different nutrient media inoculated with submerged seed mycelium and assay of the activity for 2 times, i. e. in 96 and 240 hours allowed a detection of up to 76.2 per cent of active strains out of the total number of the isolates.