Kinetic analysis of papaya proteinase omega

Papaya proteinase omega (pp omega) has been purified from dried latex both by immunoaffinity and traditional methods. Kinetic analysis revealed that (1), the pp omega-catalysed hydrolysis of N-benzoyl-L-arginine p-nitroanilide (BApNA) has a lower specificity (kcat/Km) than the same reaction catalysed by papain; (2), the pp omega-catalysed hydrolysis of a tripeptide substrate having phenylalanine at the second position (S2-site) showed a more similar specificity to that catalysed by papain; (3), the significant difference between the two enzymes is that steady state kinetics with both L-BApNA and a tripeptide enables the identification in pp omega of other ionizations affecting binding. The active sites of papain and pp omega can therefore be distinguished by pH-dependence of kcat/Km.     

Problems in the hygienic rationalization of the therapeutic and prophylactic nutrition of industrial workers

Based on generalization and analysis of instructions and guidelines for therapeutical and prophylactic diets of workers, ways of its optimization were proposed, by using bifide-containing acid dairy products as a preventive agent against possible occupational diseases caused by occupational factors.     

D. K. Zabolotny Institute of Microbiology and Virology of the Academy of Sciences of the Ukraine (to the 65th anniversary of foundation)

The paper presents the results of treating patients with chronic nonspecific diseases of the lung by the use of extracorporeal ultraviolet autoblood irradiation (EUVABI). The marked clinical effect recorded after an EUVABI course coincided with the normalization of an erythrocytic membrane morphoform, which suggests that the severity of allergic and inflammatory reactions was liquidated and blood viscosity was improved. EUVABI led to positive changes in the pattern of morphotypes in the crystallogram of plasma, except the patients who showed no clinical effect, which indicates that plasma crystallography can be used as a diagnostic test in predicting the results of EUVABI application.     

Central GABAA and GABAB receptor modulation of basal and stress-induced plasma interleukin-6 levels in mice

The development of control strategies for loiasis is of crucial importance in endemic areas and depends heavily on the accurate identification of occult-infected individuals. A polymerase chain reaction (PCR) and nested polymerase chain reaction (nested PCR) were developed and based on sequences of the repeat 3 region (15r3) of the gene encoding a Loa loa 15-kD protein. The assays was performed on 20 blood samples from occult-infected subjects and 30 from field-collected amicrofilaremic individuals. The size of the initial PCR product was 396 basepairs (bp). When this initial amplification using primers 15r3(1) and 15r3(2) was carried out for 30 cycles, the PCR products from three of the 20 occult-infected and five of the 30 amicrofilaremic individuals were visualized after electrophoresis by staining the gel with ethidium bromide. Subsequent Southern blotting and hybridization with the specific probe revealed hybridization in 19 of 20 occult-infected and 23 of 30 amicrofilaremic samples but only after two days of exposure of the blot to the x-ray film. When the nested PCR was carried out (product size = 366 bp, primers 15r3(3) and 15r3(4)), 19 of 20 occult-infected and 23 of 30 amicrofilaremic samples that were positive by Southern hybridization of the initial PCR products were strongly positive by staining with ethidium bromide. Qualitative Southern blotting of the nested PCR products using the same probe previously described confirmed the ethidium bromide staining results after a very short exposure time of 4 hr. These results demonstrate that the nested PCR amplification product is specific and that its sensitivity in detecting occult loiasis is 95%. This approach has significant promise for the screening of large human populations for active loiasis without the requirement for blotting and hybridization of the PCR products.     

Comments on ‘Evolutionary neural network modelling for software cumulative failure time prediction’ by Liang Tian and Afzel Noore [Reliability Engineering and System Safety 87 (2005) 45–51]

This paper [Tian L, Noore A. Evolutionary neural network modelling for software cumulative failure time prediction. Reliab Eng Syst Saf 2005; 87:45–51] purports to present a useful means of predicting the cumulative failure time function for software reliability growth. In fact, the nature of the ‘prediction’ is too simplistic to be of use. Furthermore, the authors' claims for the accuracy of the predictions appear to be without value.     

Water quality of Scottish rivers: spatial and temporal trends

The Harmonised Monitoring Scheme (HMS) was initiated in 1974 and represents the best-organised source of temporal and spatial data describing water quality for the major mainland rivers of Scotland, England and Wales. This paper presents the first detailed analysis of HMS data for Scotland, and identifies temporal changes in water quality from 1974 to 1995. From a concomitant analysis of catchment land cover characteristics, water quality indices have been linked with potential 'drivers' of change, influencing both point and diffuse sources. Nitrate concentrations between rivers are highly correlated with the amount of arable land, and relationships exist between grassland cover, orthphosphate-P and suspended solids concentrations. Similarly, urban catchments are highly correlated with ammonium-N, orthophosphate-P and suspended solids. Spatial and temporal trends in water quality for the rivers of Scotland are discussed.     

Development of a cost effective probe for the long term monitoring of straw bale buildings

This paper reviews current methodologies for measuring the moisture content of straw bale walls in buildings. It discusses the development of an affordable and accurate moisture probe that has been designed to be easily assembled by the builder or owner of a straw bale building from items readily available in the United Kingdom (UK). The probe uses a timber block inserted into the wall, relying upon the measurable moisture variances of the timber and relating this to the surrounding straw. The probes are designed to be used in pairs of varying length, taking measurements at different depths to give an estimate of the moisture gradient through the wall. In order to properly calibrate this device, a full set of sorption and desorption isotherms were established for both Oat and Wheat straw and three different timber species. The results from an environmental chamber have been compared to readings from specimens of the new probe installed in a straw bale house in the south west of the UK. The results were found to be consistent, to within 2%, with the laboratory findings.     

Efficient Switching and Domain Interlocking Observed in Polyaxial Ferroelectrics

We present transmission electron microscopy observations of domain wall motion in thin freestanding KNbO 3 crystals under applied electric fields. Since there is no substrate, there is no elastic clamping of 90 domains. We observe that curved and tilted 90 domain walls are the most mobile, whereas untilted 90 domain walls are resistant to field-induced motion. We explain this result in terms of two factors. First, the switching pressure on a domain wall ( P 2 m P 1 ) E is determined by the relative electrostatic energies of the neighboring polarizations P 1 and P 2 . Consequently, some 90 domain walls are immobile under certain field directions, leading to domain interlocking. Second, domain walls experiencing a high switching pressure move by a ripple mechanism, and do not move as rigid sheets. The tilted wall region in such a ripple has a polarization charge, and an associated depolarization field, which reduces the local switching barrier. An accumulation of polarization charge can result in a tilted or curved wall, as occurs at the mobile tips of 90 domain needles. Any increase in density of immobile wall configurations with cycle time represents an inherent contribution to fatigue. Uniaxial ferroelectrics, with polarizations parallel to the field, should not experience such domain interlocking.