The temperature dependence of high-resolution 1H NMR spectra of Rhodobacter sphaeroides photosynthetic reaction centres in a temperature range of 25-40 degrees C

High-resolution 1H-NMR spectra registered within a temperature range of 25-40 degrees C revealed a nonmonotonous dome-shaped temperature dependence of the ratio between integral NMR signal intensities determined at ppm intervals 2.5-4.5 and 0.2-2.5 with a maximum at 30 degrees C. This may be due to RC structural changes accompanying the temperature rise and accelerating the recombination reaction between oxidized bacteriochlorophyll and reduced primary quinone at temperatures above 30 degrees C.     

Promotive effect of abscisic acid in flowering ofChenopodium rubrum as the result of decreasing apical dominance

Abscisic acid (ABA) was applied in a concentration of 1. 10^?3 M and 1. 10^?4 M to the quantitative SD plantChenopodium rubrum under various light regimes. ABA did not influence flowering in plants under continuous illumination, enhanced flowering in plants subjected to long days and inhibited it in plants induced by short days. It was concluded that ABA can not substitute for inductive treatment but its action may be additive to initial stages of reproductive morphogenesis (enhanced growth rate and branching of the apical meristem) as evoked by long days.     

Comparative expression in Escherichia coli of the native and hybrid genes for acyl-lipid delta(9) desaturase

Expression of the desC gene coding for acyl-lipid delta(9) desaturase of thermophilic cyanobacterium Synechocystis sp. PCC6803 was studied in Escherichia coli cells. In a hybrid gene constructed (desC-licBM3), a sequence of the native acyl-lipid delta(9) desaturase was fused in frame with the reporter gene coding for thermostable lichenase. Lichenase contained in the hybrid protein simplified selection and analysis of the expression of membrane desaturase in the heterologous host. Comparisons of the expression for the native and hybrid genes in bacterial cells showed that lichenase remained active and thermostable in the hybrid protein, while desaturase retains the capability of introducing a double bound in the corresponding position of fatty acids.     

Effect of an epoxy derivative of 2′5′-trioligoadenylate on human neuroblastoma cells

We studied the effect of an epoxy derivative of dephosphorylated 2′,5′-trioligoadenylate (5′,5′ApApAepoxy) resistive to the action of cellular phosphodiesterase on cells of human neuroblastoma IMR 32 cultured in vitro. Twenty-two hours after the addition of 5·10⁻⁶ M 2′,5′ApApAepoxy to the culture medium, the number of cells decreased by 20% (P < 0.05), while the content of protein in these cells increased, on average, by 52% (P < 0.01), as compared with the control. The activities of Na⁺,K⁺-and Ca²⁺, Mg²⁺-ATPases in a microsomal fraction obtained from cells cultured in the presence of 2′, 5′ ApApAepoxy decreased by 50% (P < 0.001) as compared with those in the control cells. Our data indicate that 2′,5′ApApAepoxy possess antiproliferative activity. According to our findings, the antiproliferative effect of 2′,5′ ApApAepoxy can, to a great extent, be explained by the fact that this oligoadenylate derivative significantly modulates the activities of Na⁺,K⁺-and Ca²⁺,Mg²⁺-ATPases. Neirofiziologiya/Neurophysiology, Vol. 38, No. 2, pp. 97–102, March–April, 2006.     

Viral hepatitis E: its epidemiological characteristics in the Republic of Tajikistan

The characteristic feature of the Republic of Tajikistan, as well as other republics of Central Asia, is the wide spread of virus hepatitis E. The epidemiology of this grave disease, recently known as virus hepatitis non A, non B with the fecal-oral mechanism of transmission of this infection, has been yet insufficiently studied. The article points out to the specific character of this infection which essentially differs, both epidemiologically and clinically, from other enteric hepatitis (hepatitis A), also hyperendemic for the republic. The results of the study of the immunostructure of the population with respect to both hepatitis E and hepatitis A are presented.     

Activity of fruit-piercing moths, Eudocima spp. (Lepidoptera: Noctuidae), in north Queensland crops: Some effects of fruit type, locality and season

Fruit-piercing moth activity was assessed in lychee or carambola crops on the wet tropical coast and on the dry tropical tablelands of north-eastern Queensland between 1985 and 1993. Monitoring occurred at fruiting, from 30 min after sundown for 1 h by systematically inspecting orchard trees under torchlight. Six species were recorded: Eudocima fullonia (Clerck), Eudocima jordani (Holland), Eudocima materna (L.), Eudocima salaminia (Cramer), Eudocima aurantia (Moore) and Eudocima cocalus (Cramer). Moths were detected between November and August, with activity lowest during the driest months (July–October) when fruit availability also decreased. Most annual variation in moth numbers occurred at the beginning of the wet season (November–December) when lychees cropped. The principal species recorded at all three sites on both fruit types between November and mid-March was E. fullonia . It represented 95.5% of the moths on coastal lychees. During autumn, the major species in carambola crops were E. jordani on the coast and E. materna on the tablelands (where total activity was only about half that in the coastal crop). Over all sampling years, 77.9% of all moths caught on coastal fruit were males, compared to 51.4% on tableland fruit. Of the female moths dissected from all sites, 77.7% contained spermatophores and fully developed eggs. An assessment of moth activity through a single night (19.00–05.00 h) in coastal carambolas showed that 72.9% of all moths arrived before midnight. The results indicate that there are opportunities in tableland areas for fruit production during the dry season without the need for control measures.     

The effect of the substance exin on development of microbial infections and isolation of ethylene in plants

Effects of Exin on infection of tomato, potato, and cabbage plants with Pseudomonas solanacearum and Erwinia carotovora and a fungus Sclerotium rolfsii were studied. The treatment of infected plants with Exin caused no significant effect on the development of the disease. Treatment with streptomycin as a standard for comparison completely inhibited the growth of these microorganisms. Pretreatment with Exin one to eight days before infecting inhibited the development of diseases. The numbers of tomato and potato plants damaged among those infected with P. solanacearum were lower by 10 and 35% respectively. In field experiments (350 plants per variant), treatment with Exin decreased the development of wilt caused by S. rolfsii and P. solanacearum and rot caused by E. carotovora. Treatment with Exin activated the release of ethylene for not less than 30 days. Possible mechanisms of the effects of Exin are discussed.     

Sea urchin sperm DNP. I. Chemical composition and template properties of DNP

Electrophoretic mobility, amino acid composition and salt dissociation of histones isolated from sperm of sea urchin Strongylocentrotus intermedius and calf thymus cells were studied. The special arginine-rich histone fraction (I) has been observed in sea urchin sperm chromatin, this fraction being absent in calf thymus chromatin. Dissociation of lysine-containing histone fractions from sea urchin chromatin occured in the range of 0.7 to 1.0 M NaCl concentrations. H1 of calf thymus chromatin was totally extracted with 0.6 M NaCl. In the course of a further increase of salt concentrations (up to 1.5 M NaCl) a practically total extraction of histones from sperm chromatin was observed, while about 20% of proteins remained bound to DNA in thymus chromatin after extraction with 2.0 M NaCl. The template activity of non-extracted DNP preparations from urchin sperm was equal to 2-3% of that of totally deproteinized DNA. The template activity of DNP gradually increased at protein extraction from DNP preparations. The hybridization capacity of RNA transcribed on partially dehistonized DNP templates in vitro also increased.     

Effect of pineal peptide on parameters of the biological age and life span in mice

Female CBA mice were injected with s.c. synthetic tetrapeptide Epithalon from a 6-month age until death. The drug failed to affect the body weight or food consumption, physical activity or behavioural parameters. However, it slowed down the age-related switching off of the estrus function, decreased body temperature, decelerated free redical processes, prolonged the mice life span with an accompanying drop in spontaneous tumour incidence.