Comparative study of cytomegalovirus (CMV) antigenemia assay, polymerase chain reaction, serology, and shell vial assay in the early diagnosis and monitoring of CMV infection after renal transplantation

BACKGROUND: Early diagnosis of cytomegalovirus (CMV) infection, which is an important cause of morbidity and mortality in renal transplant recipients, remains of great importance. This prospective study was performed in kidney transplant recipients to determine the diagnostic value of the CMV antigenemia assay in comparison with polymerase chain reaction (PCR), serology, and shell vial assay. METHODS: Seventy-five consecutive renal transplant recipients were enrolled in this study and monitored by both antigenemia assay and serology. The initial 34 of the 75 patients were subjected to PCR and shell vial assay. RESULTS: Antigenemia, PCR, and shell vial assay became positive before the onset of CMV-related symptoms in 31/34 (89%), 13/16 (81%), and 2/16 (13%), respectively. None of the 34 patients who had symptomatic CMV disease showed a significant increase in IgG or IgM before the onset of symptoms. Antigenemia and PCR assays turned positive, 7 and 11 days (median), respectively, before the onset of clinical symptoms. Serology and shell vial assay became positive 21 and 25 days (median), respectively, after the onset of CMV-related clinical symptoms. To examine the clinical value of these assays, "good correlation" was defined based on the correlation between the clinical course and the results of the assays. Good correlation with the antigenemia assay was observed in 33 (96%) out of 34 renal transplant recipients who recovered from their CMV disease after ganciclovir therapy. Only one of 16 (7%) patients showed good correlation by shell vial assay, whereas PCR and serology did not show a good correlation. Consequently, antigenemia was considered the best way to monitor CMV infections after kidney transplantation. CONCLUSIONS: Only the CMV antigenemia assay can be successfully employed after renal transplantation for the early diagnosis and extensive monitoring of active CMV infection.     

Global leaf companies control the tobacco market in Malawi

Objective

To examine the influence of US‐based tobacco leaf‐buying companies, Universal Corporation and Alliance One International, on Malawi''s economy and trade policy in 2000–6.

Design

Analyses of ethnographic data and tobacco industry documents.

Results

Universal Corporation and Alliance One International, through their subsidiary companies Limbe Leaf and Alliance One, respectively, in Malawi, control policy‐making advisory groups and operate a tobacco cartel to influence Malawi''s economic and trade sectors. Limbe Leaf''s corporate secretary and lawyer is a member of several policy‐making committees that advise the Malawi government on tobacco‐related trade policy. The corporate representative''s presence prevents other committee members from taking positions against the tobacco industry and ensures government policy that advances industry interests to obtain low‐cost tobacco. The World Bank and Malawi''s Anti‐corruption Bureau report allegations of collusion between Limbe Leaf and Alliance One over prices at tobacco markets. Allegations of collusion between Limbe Leaf and Alliance One prompted Malawi President Bingu Mutharika in 2006 to warn the companies to end non‐competitive practices or leave the country, but there was no meaningful follow‐up action. Findings from interviews with small‐scale tobacco traders in Malawi suggest that Universal and Alliance One International purchase smuggled raw tobacco from the neighbouring countries, Zambia and Mozambique, undermining growers'' efforts to benefit from tobacco farming in Malawi.

Conclusion

These actions restrict competition, depress tobacco prices for Malawi''s farmers and contribute to poverty in Malawi, while keeping the country dependent on tobacco growing.Malawi (fig 1​1)) is the 13th poorest country in the world.¹ In all, 76% of Malawians, survive on less than US$2 (£1.02, €150) per day.¹ Malawi derives 65% of its foreign earnings from tobacco, making Malawi the most tobacco‐reliant country in the world.² Tobacco accounts for 43% of the agricultural gross domestic product,³ 13% of the overall gross domestic product⁴ and 23% of Malawi''s total tax base.⁴ Out of a total workforce of 5 million people, between 600 000 and 2 million people are employed in Malawi''s tobacco sector.⁵ Land devoted to tobacco growing in Malawi occupies 122 000 hectares out of 4.6 million hectares under cultivation.^6,7 Over 98% of Malawi''s leaf (mostly burley tobacco^8,9) is exported to 68 countries,^3,5,10 with the European Union (EU; 44% of exports) and US (13% of exports) being the top destinations.¹¹ US‐based leaf‐buying companies Universal Corporation and Alliance One International purchase Malawi''s tobacco and sell it to Philip Morris and British American Tobacco (BAT).Open in a separate windowFigure 1 Malawi is a landlocked country that transports its tobacco overland to ports in Mozambique and South Africa. Smuggling raw tobacco occurs in both directions along Malawi''s borders with Zambia and Mozambique (shaded area).Tobacco Journal International, a tobacco industry trade publication, reported in September 2006 that low and uncertain tobacco prices in Malawi created friction between tobacco farmers and leaf‐ buying companies.^12,13 This trade publication, however, did not analyse the role of leaf companies, through their buying practices, in influencing tobacco prices or identify the cigarette manufacturers as the beneficiaries of Malawi''s low and uncertain tobacco prices. Our study goes beyond the Tobacco Journal International report to reveal how leaf companies and manufacturers hide behind explanations of supply and demand to deflect discussion on tobacco sectors and public dialogue on tobacco prices in Malawi from the economic practices of leaf companies and manufacturers to market forces. The purpose of this paper is to show the ways Universal and Alliance One, the main buyers of Malawi''s tobacco, control the local tobacco sector, influence Malawi''s trade policy to ensure access to low‐cost raw tobacco and depress raw tobacco prices, preventing Malawi from benefiting from tobacco growing.     

Assembling nanowires from Mo-S clusters and effects of iodine doping on electronic structure

Using ab initio calculations, we find high stability of octahedral Mo6S8 clusters, which can further be condensed to form Mo3nS3n+2 (n, an integer) nanowires. These linear structures are energetically more favorable compared with other closed-packed polyhedral isomers of Mo-S clusters. The octahedral units in nanowires are stabilized by strong Mo-Mo interactions and p-d hybridization between Mo 4d and S 2p orbitals. There is a free electron-like band that crosses the Fermi energy in infinite nanowires and leads to their metallic character. Iodine doping acts as electron donor and can be used to tailor the electronic conductivity. For Mo12S8I4 nanowires, both electrons and holes are found to contribute to conduction. These nanowires are energetically more favorable than the experimentally obtained Mo12S6I12 nanowires.     

Analog implementation of pulse-coupled neural networks

This paper presents a compact architecture for analog CMOS hardware implementation of voltage-mode pulse-coupled neural networks (PCNN). The hardware implementation methods shows inherent fault tolerance specialties and high speed, which is usually more than an order of magnitude over the software counterpart. A computational style described in this article mimics a biological neural network using pulse-stream signaling and analog summation and multiplication, pulse-stream encoding technique uses pulse streams to carry information and control analog circuitry, while storing further analog information on the time axis. The main feature of the proposed neuron circuit is that the structure is compact, yet exhibiting all the basic properties of natural biological neurons. Functional and structural forms of neural and synaptic functions are presented along with simulation results. Finally, the proposed design is applied to image processing to demonstrate successful restoration of images and their features.     

Screening for yeasts incorporating the exogenous eicosapentaenoic and docosahexaenoic acids from crude fish oil

The screening for yeasts incorporating exogenous eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into their cellular lipids was conducted. Two percent of oil from fish scraps was added to a yeast isolation medium as a sole carbon source. From 143 soil samples, we isolated 23 yeast strains, nine of them were found to be capable of quickly assimilating the scrap fish oil. These nine strains, in addition to four previously isolated triglyceride-assimilating and lipase-producing strains, Yarrowia lipolytica and three Geotrichum species (FO274A, FO347-2 and FO401B), were cultured in a growth medium at 30 degrees C. Strains FO726A, FO765A and FO347-2 were selected on the basis of dry cell weight production and ability to store EPA and DHA in their cells, and their performance was further compared by varying cultivation temperature and time. From 1 g of the scrap fish oil, FO726A yielded 620 mg of dry cells, containing 47.1% lipid, 38.1% triglyceride, 3.3% EPA, and 4.9% DHA, when cultured at 25 degrees C for 36 h. Strain FO726A apparently has the highest ability to incorporate EPA and DHA into its cellular lipids. Results from further experiments showed that the incorporated EPA and DHA mainly existed in the form of triglyceride in the FO726A cell. These results suggest that FO726A is suitable for the production of cell mass rich in EPA and DHA for feed.     

Effects of Intermittent Hypoxia on Cytokine Expression Involved in Insulin Resistance

Sleep apnea syndrome (SAS) is a prevalent disorder characterized by recurrent apnea or hypoxia episodes leading to intermittent hypoxia (IH) and arousals during sleep. Currently, the relationship between SAS and metabolic diseases is being actively analyzed, and SAS is considered to be an independent risk factor for the development and progression of insulin resistance/type 2 diabetes (T2DM). Accumulating evidence suggests that the short cycles of decreased oxygen saturation and rapid reoxygenation, a typical feature of SAS, contribute to the development of glucose intolerance and insulin resistance. In addition to IH, several pathological conditions may also contribute to insulin resistance, including sympathetic nervous system hyperactivity, oxidative stress, vascular endothelial dysfunction, and the activation of inflammatory cytokines. However, the detailed mechanism by which IH induces insulin resistance in SAS patients has not been fully revealed. We have previously reported that IH stress may exacerbate insulin resistance/T2DM, especially in hepatocytes, adipocytes, and skeletal muscle cells, by causing abnormal cytokine expression/secretion from each cell. Adipose tissues, skeletal muscle, and the liver are the main endocrine organs producing hepatokines, adipokines, and myokines, respectively. In this review, we focus on the effect of IH on hepatokine, adipokine, and myokine expression.     

Reliable Differentiated Services Optimization for Network Coding Cooperative Communication System

Software-Defined Networking (SDN) is a new network architecture with flexibility and scalability, researchers introduced the core idea of SDN into wireless network, and a cooperative communication system based on network coding is proposed. In this paper, we carry on an investigation in differentiated service strategy of network coding cooperative communication system. The meaning of differentiated services is for the different applications take different power for data transmission and the transmission power is associated with their reliability needs. In other words, transmission power control is performed in the presence of known reliability, we named the scheme Reliability-Bounded Transmission Power Control (RTPC) scheme. The RTPC scheme changes the way in which all the applications in the past have been able to maintain the power to be transmitted, but the reliability requirements of different applications will be transmitted with different transmission power. In addition, because of the nodes that far away from the sink node still exist a lot of energy when the network died, so consider to improve the transmission power of non-hotpots nodes in order to increase the reliability of data transmission. The experimental results show that the RTPC scheme can greatly improve the transmission reliability without affecting the network lifetime.     

Determining factors for anodic polarization curves of typical structural materials of boiling water reactors in high temperature – high purity water

In order to examine the anodic polarization characteristics of typical structural materials of boiling water reactors (BWRs), the anodic polarization curves of type 316L stainless steel (316L SS) and Alloy 182 were measured in deaerated high purity water at 553 K using the previously reported measurement method which was confirmed suitable for high temperature – high purity water. In order to specify which constituent element determines the dissolution characteristics of these materials, the anodic polarization curves of pure iron, pure nickel, and pure chromium were also surveyed. The anodic polarization curve of 316L SS was determined to have active, passive, and transpassive states which were the same as type 304 SS (304 SS) showed. But, Alloy 182 had different polarization characteristics especially near the corrosion potential as it had no active state. From comparison results of the polarization characteristics of these materials and their constituent elements, the corrosion characteristics of these materials were concluded to be mainly determined by the corrosion characteristics of chromium.     

Improved sublimation growth of single crystals of thiophene/phenylene co-oligomers

We have improved the sublimation recrystallization method using a handmade sublimation apparatus and optimizing various physical conditions. The improved apparatus comprises two closely aligned heaters and enables us to grow the large thiophene/phenylene co-oligomer (TPCO) crystals of high quality. We found it essential and effective for the crystal growth to adjust temperatures of these heaters and their temperature difference of ca. 40-50 °C. We fabricated organic field effect transistor (OFET) devices with the resulting crystals of a TPCO. Those devices show the p-type FET characteristics. The field effect mobilities increased with smaller thicknesses of the crystals; the maximum mobility recorded was 0.021 cm²/Vs.