Factors responsible for transition of the <Emphasis Type="Italic">Duddingtonia flagrans</Emphasis> carnivorous fungus from the saprotrophic to the zootrophic nutrition type

Quantitative investigation of the factors responsible for trap formation in the nematophagous fungus Duddingtonia flagrans F-882 in submerged liquid culture was carried out. The data obtained suggest a complex program for the regulation of zootrophic nutrition in D. flagrans. Optimal concentrations of such carbon and nitrogen sources as sucrose (0.4%), ammonium ions (0.2%), and tryptone (0.2%) promote trap formation in the case of contact with the nematodes Panagrellus redivivus. Increased concentrations of these compounds, however, inhibit trap formation. The sensitivity of the mycelium to nematode excreta depends on the state of the culture and is increased under limitation by certain nutrient components or in the course of prolonged starvation. A direct correlation was found between the number of caught nematodes and the number of chlamydospores formed on the mycelium. The nutrients obtained from the nematode biomass are used for formation of additional chlamydospores (on average, about 20 chlamydospores per nematode). Environmental and evolutionary aspects of the role of zootrophic nutrition in carnivorous fungi are discussed.     

Effect of a short-term dietary creatine supplementation on high-energy phosphates in the rat myocardium.

The aim of this study was to find out whether creatine (Cr) feeding affects total creatine (TCr), phosphocreatine (PCr), adenine nucleotide contents and beta-hydroxy-acyl-CoA-dehydrogenase (HAD) activity in myocardium as compared to red skeletal muscle. Ten adult Wistar rats received Cr (2.5% of diet weight) for 7 days. In Cr fed rats, PCr was increased (by approx. 20%) in cardiac and in soleus muscles with ATP elevated in myocardium and TCr and free Cr in soleus. In both muscles, Cr feeding enhanced HAD activity. It is concluded, that dietary Cr does increase cardiac muscle high energy phosphate reserves and its oxidative potential.     

Encapsulation of recombinant <Emphasis Type="Italic">E. coli</Emphasis> expressing cyclopentanone monooxygenase in polyelectrolyte complex capsules for Baeyer–Villiger biooxidation of 8-oxabicyclo[3.2.1]oct-6-en-3-one

Recombinant Escherichia coli cells, over-expressing cyclopentanone monooxygenase activity, were immobilized in polyelectrolyte complex capsules, made of sodium alginate, cellulose sulfate, poly(methylene-co-guanidine), CaCl₂ and NaCl. More than 90% of the cell viability was preserved during the encapsulation process. Moreover, the initial enzyme activity was fully maintained within encapsulated cells while it halved in free cells. Both encapsulated and free cells reached the end point of the Baeyer–Villiger biooxidation of 8-oxabicyclo[3.2.1]oct-6-en-3-one to 4,9-dioxabicyclo[4.2.1]non-7-en-3-one at the same time (48 h). Similarly, the enantiomeric excess above 94% was identical for encapsulated and free cells.     

Effect of rad 54 mutation on the ability of Saccharomyces cerevisiae cells to recover from radiation and thermal injury

The diploid cells of Saccharomyces cerevisiae carrying rad 54 homozygous mutation do not exhibit an ability for any considerable "rapid" postirradiation and post-hyperthermic recovery. A pretreatment with high temperature (50 degrees C) increases the radiation response of mutant cells. Survival of cells overheated before gamma-irradiation is increased by keeping them in water for 2-6 h at 28 degrees C, while the corresponding value of survival for cells treated by each of the factors delivered separately remains constant in these conditions.     

Hemodynamic and neuroendocrine predictors of lower body negative pressure (LBNP) intolerance in healthy young men.

Exposure to LBNP results in body fluid shift to lower extremities similarly as under influence of orthostatic stress. In susceptible persons it leads to syncope. For better understanding why certain individuals are more susceptible to orthostatic challenges it seemed necessary to collect more data on hemodynamic and neuroendocrine adjustments occurring before onset of presyncopal symptoms Accordingly, in this study heart rate (HR), blood pressure (BP), stroke volume (SV), cardiac output (CO), hematocrit, plasma catecholamines, adrenomedullin, ACTH and plasma renin activity (PRA) were measured in 24 healthy men during graded LBNP (-15, -30 and -50 mmHg). Thirteen subjects completed the test (HT group) whereas 11 had presyncope signs or symptoms at -30 mmHg or at the beginning of -50 mmHg (LT group). Comparison of these groups showed that LT subjects had lower baseline total peripheral resistance and higher plasma adrenomedullin. During LBNP plasma catecholamine and PRA increases were even greater in LT than in HT group while plasma adrenomedullin elevations were similar in both groups. Plasma ACTH increased only in LT group following presyncope symptoms. Low tolerant group showed more rapid decline of SV and CO than HT subjects from the beginning of LBNP. It is suggested that measurements of SV at the level of LBNP which did not evoke any adverse symptoms may be of predictive value for lower orthostatic tolerance.     

Cerebral angiogenesis after subarachnoid hemorrhage (SAH) and endothelin receptor blockage with BQ-123 antagonist in rats.

The aim of the study was to determine the effect of chronic vasospasm after SAH on angiogenesis and the effect of endothelin-1, the main causative factor in vasospasm, on this process. Male Wistar rats, 220-250 g, were examined. Seven days after cannulation of the cisterna magna (CM), a 100 microl dose of non-heparinized blood was administered to induce SAH. Sham SAH (aSAH) was induced by intracisternal injection of 100 microl of artificial cerebrospinal fluid. Endothelin receptor antagonist BQ-123 in a dose of 40 nmol in 50 microl of cerebrospinal fluid was given three times: 20 min. before SAH and aSAH, 60 min and 24 hours after SAH and aSAH. The same pattern of BQ-123 administration was used in the nonSAH group. The brains were removed 48 hours later for histological evaluation. Vascular surface density was measured in cerebral hemisphere sections (at the level of the dorsal part of the hippocampus) and brain stem sections (1/2 of the pons). An increase in angiogenesis was observed after SAH, compared to control values. The administration of BQ-123, a specific endothelin receptor blocker inhibits angiogenesis in cerebral hemispheres after SAH.     

Effect of Temperature on the Taxonomic Structure of Soil Bacterial Communities during Litter Decomposition

Microbiology - Effect of temperature on succession changes of the saprotrophic bacterial community of gray forest soil in the course of decomposition of aspen leaves and branches was studied in...