Thrombolytic therapy for unstable angina

Thrombolytic therapy for unstable angina has not gained acceptance as a primary treatment for unstable angina (UA) despite the evidence showing a reduction in mortality when these agents are given for myocardial infarction. The purpose of this review is to examine the clinical value of thrombolytic therapy for UA. The multiple lines of evidence supporting intracoronary thrombus formation as a key mechanism in the pathogenesis of UA are reviewed. Studies examining the effect of thrombolytic therapy on angiographic endpoints have shown little effect on the extent of luminal narrowing, but do reveal a decrease in angiographically detected thrombus. Twelve randomized, controlled trials of thrombolytic agents in 611 UA patients with predefined clinical endpoints have been published. These trials varied widely in design and adjunctive therapy both in treated and control grops. Review of these trials show a tendency to fewer clinical events such as death, infarction, and need for revascularization in treated patients, with a corresponding increase in bleeding complications. Clinical efficacy of thrombolytic therapy cannot be excluded by the available data, perhaps in part because of insufficient numbers of patients treated. Determination of the net clinical value of thrombolytic therapy must await larger and more definitive trials.     

Joint Source–Channel Communication for Distributed Estimation in Sensor Networks

Power and bandwidth are scarce resources in dense wireless sensor networks and it is widely recognized that joint optimization of the operations of sensing, processing and communication can result in significant savings in the use of network resources. In this paper, a distributed joint source-channel communication architecture is proposed for energy-efficient estimation of sensor field data at a distant destination and the corresponding relationships between power, distortion, and latency are analyzed as a function of number of sensor nodes. The approach is applicable to a broad class of sensed signal fields and is based on distributed computation of appropriately chosen projections of sensor data at the destination - phase-coherent transmissions from the sensor nodes enable exploitation of the distributed beamforming gain for energy efficiency. Random projections are used when little or no prior knowledge is available about the signal field. Distinct features of the proposed scheme include: (1) processing and communication are combined into one distributed projection operation; (2) it virtually eliminates the need for in-network processing and communication; (3) given sufficient prior knowledge about the sensed data, consistent estimation is possible with increasing sensor density even with vanishing total network power; and (4) consistent signal estimation is possible with power and latency requirements growing at most sublinearly with the number of sensor nodes even when little or no prior knowledge about the sensed data is assumed at the sensor nodes.     

Interaction of short chain and long chain fatty acid phosphoglycerides and bile salts with prothrombin

An equimolar mixture of phosphatidylserine and (dioleoyl) phosphatidyl-ethanolamine could substitute for brain cephalin preparations in the single stage prothrombin assay. However, no clot promoting activity was observed on the addition of any of the individual long chain fatty acid-containing phospholipids. Short chain fatty acid-containing phospholipids, such as diheptanoylphosphatidylcholine, diheptanoylphosphatidylethanolamine, diheptanoylphosphatidic acid, and dihexanoylphosphatidylcholine, or dihexanoylphosphatidylethanolamine were inhibitory under all conditions studied. Similar effects of these two general classes of phospholipids were observed in a two-stage thrombin generation system, in which a mixture of bovine Factor Xa, Factor Va, and Ca2+ were interacted with prothrombin. In the presence of 25 mM Ca2+, dioleoylphosphatidic acid or brain phosphatidylserine alone, and with other long chain phospholipids, formed complexes with bovine plasma prothrombin. On the other hand, dioleoyl-, diheptanoyl- or dihexanoylphosphatidylcholine under comparable conditions showed no binding to prothrombin. There appeared to be a small degree of binding of diheptanoylphosphatidic acid to prothrombin, but it was insufficient to cause any significant change in apparent molecular weight of prothrombin. A mixture of prothrombin, Factor V, diheptanoylphosphatidic acid/diheptanoylphosphatidylcholine and Ca2+ eluted in the void volume of Sephadex G-200, but showed a much reduced coagulant activity. Though a net negative charge on the phospholipid surface is required for phospholipid-protein interactions, this does not necessarily promote coagulant activity. Bile acids and bile salts, such as cholic acid, deoxycholic acid, taurocholic acid, glycocholic acid, lithocholic acid and dehydrocholic acid, exerted varying levels of stimulation on the prothrombin assay and thrombin generation system, but were not as effective as the phospholipids. Interestingly, no interaction of these bile acids or salts with prothrombin was noted in the presence of Ca2+. The results of these experiments suggest that negatively charged micelles per se are not sufficient for binding alone and that other chemical and physical characteristics of phospholipids are of prime importance.     

Nutritional characterization of high protein and high lysine barley lines

Six high protein and high lysine barley lines were derived from four crosses involving high protein andlor high lysine donors, ie Riso 1508 and SV 73608 (Hiproly×Mona⁵), with well adapted local strains V 5681 and V 4342. The trial was grown at the Wheat Research Institute, Faisalabad, Pakistan. The lines were chemically and nutritionally characterized and the results were compared with the parents. The biological value, net protein utilization and lysine contents were higher in all the derived lines than in their local parents, ie V 5681 and V 4342. The increased lysine levels in the lines B 82503 and B 82507 may be a consequence of the reduction of prolamin fractions with simultaneous increases in salt soluble fractions. In all the lines, lysine and nutritional quality increase were a reflection of high protein andlor high lysine parents. The line B 82503 had grain yield comparable to its local parent V 5681 but it was superior in lysine and some nutritional attributes to its high lysine donor parent Riso 1508. In some lines, lysine improvement was achieued without impairing grain yield.     

Nanostructured materials with biomimetic recognition abilities for chemical sensing

Binding features found in biological systems can be implemented into man-made materials to design nanostructured artificial receptor matrices which are suitable, e.g., for chemical sensing applications. A range of different non-covalent interactions can be utilized based on the chemical properties of the respective analyte. One example is the formation of coordinative bonds between a polymerizable ligand (e.g., N-vinyl-2-pyrrolidone) and a metal ion (e.g., Cu(II)). Optimized molecularly imprinted sensor layers lead to selectivity factors of at least 2 compared to other bivalent ions. In the same way, H-bonds can be utilized for such sensing purposes, as shown in the case of Escherichia coli. The respective molecularly imprinted polymer leads to the selectivity factor of more than 5 between the W and B strains, respectively. Furthermore, nanoparticles with optimized Pearson hardness allow for designing sensors to detect organic thiols in air. The ‘harder’ MoS₂ yields only about 40% of the signals towards octane thiol as compared to the ‘softer’ Cu₂S. However, both materials strongly prefer molecules with -SH functionality over others, such as hydrocarbon chains. Finally, selectivity studies with wheat germ agglutinin (WGA) reveal that artificial receptors yield selectivities between WGA and bovine serum albumin that are only about a factor of 2 which is smaller than natural ligands.     

Effect of green manure on the yield,N uptake and floodwater properties of a flooded rice,wheat rotation receiving15N urea on a highly permeable soil

Field studies were conducted for two years on a rapidly percolating loamy sand (Typic Ustochrept) to evaluate the effect of green manure (GM) on the yield,¹⁵N recovery from urea applied to flooded rice, the potential for ammonia loss and uptake of residual fertilizer N by succeeding crops. The GM crop ofSesbania aculeata was grownin situ and incorporated one day before transplanting rice. Urea was broadcast in 0.05 m deep floodwater, and incorporated with a harrow. Green manure significantly increased the yield and N uptake by rice and substituted for a minimum of 60 kg fertilizer N ha^–1. The recovery of fertilizer N as indicated by¹⁵N recovery was higher in the GM + urea treatments. The grain yield and N uptake by succeeding wheat in the rotation was slightly higher with GM. The recovery of residual fertilizer N as indicated by the¹⁵N recovery in the second, third and fourth crops of wheat, rice and wheat was only 3, 1 and 1 per cent of the urea fertilizer applied to the preceding rice crop. Floodwater chemistry parameters showed that the combined use of the GM and 40 kg N ha^–1 as urea applied at transplanting resulted in a comparatively higher potential for NH₃ loss immediately after fertilizer application. The actual ammonia loss as suggested by the¹⁵N recoveries in the rice crop, however, did not appear to be appreciably larger in the GM treatment. It appeared the ammonia loss was restricted by low ammoniacal-N concentration maintained in the floodwater after 2 to 3 days of fertilizer application.     

Optical absorption and infrared spectroscopic analysis of γ-irradiated ZnO-BaO-B2O3 glasses

A new series of borate glasses containing ZnO and BaO as network modifiers with compositions of xZnO-2xBaO-(1 − 3x)B₂O₃ (x varying from 0.10 to 0.21 mol fraction) were prepared by conventional melt quenching. Optical and structural properties were determined before and after successive γ-ray irradiation at 2.5 kGy dose using, UV-vis and Fourier transform infrared spectroscopic techniques to elucidate the effect of γ-irradiation. The results are supported by additional density and molar volume studies.     

Adenovirus-mediated delivery of rhodopsin-promoted bcl-2 results in a delay in photoreceptor cell death in the rd/rd mouse

Gene transfer to retinal cells may provide a means to retard photoreceptor cell death and thus prevent blindness in diseases such as retinitis pigmentosa. We tested the possibility of interfering with apoptotic photoreceptor cell death in the rd mouse through subretinal delivery of a recombinant replication-defective adenovirus containing the human cDNA for bcl-2, Ad.2.5HRPbcl-2. Photoreceptor-specific transgene expression was accomplished through incorporation of the 2.5 kb human rhodopsin upstream fragment (HRP). Ad.2.5HRPbcl-2 was injected alone or in combination with Ad.CMVPDE beta. Ad.CMVPDE beta contains a cDNA encoding the beta subunit of cGMP phosphodiesterase (PDE beta). Recombinant viruses containing lacZ (driven either by the cytomegalovirus (CMV) promoter/enhancer or HRP) and of Ad.CMVPDE beta and vehicle alone were injected in contralateral eyes as control. Injection of Ad.2.5HRPbcl-2 in the rd mouse resulted in histologically detectable rescue lasting 6 weeks after birth. Extent of rescue was not as large as after delivery of wildtype PDE beta, the gene defective in the rd mouse. However, delivery of genes which prevent apoptotic cell death may have broad application to gene therapy of retinal degenerative diseases.     

Time-delay/Doppler scattering function for suburban mobile radio propagation at 436 MHz

Time-delay/Doppler scattering functions are presented for two different suburban locations where multipath propagation is evident. The major features of the scattering functions are explained in terms of the surrounding environment and the street orientation with respect to the transmitter.