The treatment of peripapillary diverticula of the duodenum

An original operation is proposed for localization of the diverticulum in the descending portion of the duodenum which excludes traumas of the pancreas. Clinical observations are described.     

Respiratory symptoms and bronchial responsiveness are related to dietary salt intake and urinary potassium excretion in male children

Six men were accidentally exposed to NO2 when they were changing a propeller using a gas burner in the poorly ventilated hold of a ship. All of them were admitted to hospital with shortness of breath and cough. Chest X-ray on admission revealed diffuse, patchy and infiltrative shadows, leading to the diagnosis of pulmonary edema in all five patients. Steroid therapy was effective and followed by a quick recovery in all patients. None developed third phase manifestations characterized pathologically by bronchiolitis obliterans.     

Thyroid doses resulting from the Ukraine Chernobyl accident--Part I: Dose estimates for the population of Kiev

In the context of the radiation exposure of the Ukrainian population resulting from the Chernobyl accident, the quantification of the thyroid doses due to iodine incorporation is of special interest. This first part of a series of planned publications deals with the dose and risk estimation for Kiev citizens. Although these doses are expected to be considerably lower than those for some other regions of Ukraine, the investigations started with this population because the quantification of the thyroid doses due to iodine incorporation is of special interest. This first part of a series of planned publications deals with the dose and risk estimation for Kiev citizens. Although these doses are expected to be considerably lower than those for some other regions of Ukraine, the investigations started with this population because of the availability of rather reliable measurements and because of the size of this population. The methods developed allowed the estimation of individual thyroid doses. The average values of individual thyroid doses for five age groups (birth years 1983-1986, 1979-1982, 1975-1978, 1971-1974, and < 1971) are 104, 62, 19, 18, and 41 mGy, respectively. The collective thyroid doses were estimated as 83 x 10(3) person-Gy for those born before 1971 and as 38 x 10(3) person-Gy for younger inhabitants. The numbers of expected thyroid cancers in the whole Kiev population are 66 and 130, respectively.     

Envelope glycoprotein gp120 of human immunodeficiency virus type 1 alters ion transport in astrocytes: implications for AIDS dementia complex

Infection by human immunodeficiency virus type 1 (HIV-1) is often complicated by a variety of neurological abnormalities. The most common clinical syndrome, termed acquired immunodeficiency syndrome (AIDS) dementia complex, presents as a subcortical dementia with cognitive, motor, and behavioral disturbances and is unique to HIV-1 infection. The pathogenesis of this syndrome is poorly understood but is believed to involve interactions among virally infected macrophages/microglia, astrocytes, and neurons. In this study, we show that exposure of primary rat and human astrocytes to heat-activated HIV-1 virions, or to eukaryotically expressed HIV-1 and HIV-2 envelope glycoproteins (gp120) stimulates amiloride-sensitive Na+/H+ antiport, potassium conductance, and glutamate efflux. These effects are blocked specifically by amiloride, an inhibitor of Na+/H+ antiport and by the selective removal of gp120 with immobilized monoclonal antibody. As a result of modulation of astrocytic function by gp120, the ensuing neuronal depolarization and glutamate exposure could activate both voltage-gated and N-methyl-D-aspartate-regulated Ca2+ channels, leading to increases in intraneuronal Ca2+ and neuronal death. These findings implicate the astrocyte directly in the pathogenesis of AIDS dementia complex.     

Application-specific instruction set processor for SoC implementation of modern signal processing algorithms

A novel application-specific instruction set processor (ASIP) for use in the construction of modern signal processing systems is presented. This is a flexible device that can be used in the construction of array processor systems for the real-time implementation of functions such as singular-value decomposition (SVD) and QR decomposition (QRD), as well as other important matrix computations. It uses a coordinate rotation digital computer (CORDIC) module to perform arithmetic operations and several approaches are adopted to achieve high performance including pipelining of the micro-rotations, the use of parallel instructions and a dual-bus architecture. In addition, a novel method for scale factor correction is presented which only needs to be applied once at the end of the computation. This also reduces computation time and enhances performance. Methods are described which allow this processor to be used in reduced dimension (i.e., folded) array processor structures that allow tradeoffs between hardware and performance. The net result is a flexible matrix computational processing element (PE) whose functionality can be changed under program control for use in a wider range of scenarios than previous work. Details are presented of the results of a design study, which considers the application of this decomposition PE architecture in a combined SVD/QRD system and demonstrates that a combination of high performance and efficient silicon implementation are achievable.     

Development of composite tissue scaffolds containing naturally sourced mircoporous hydroxyapatite

The aims of this work were to investigate the conversion of a marine alga into hydroxyapatite (HA), and furthermore to design a composite bone tissue engineering scaffold comprising the synthesised HA within a porous bioresorbable polymer. The marine alga, Phymatolithon calcareum, which exhibits a calcium carbonate honeycomb structure, with a natural architecture of interconnecting permeable pores (microporosity 4–11 μm), provided the initial raw material for this study. The objective was to convert the alga into hydroxyapatite while maintaining its porous morphology using a sequential pyrolysis and chemical synthesis processes. Semi-quantitative XRD analysis of the post-hydrothermal material (pyrolised at 700–750 °C), indicated that the calcium phosphate (CaP) ceramic most likely consisted of a calcium carbonate macroporous lattice, with hydroxyapatite crystals on the surface of the macropores. Cell visibility (cytotoxicity) investigations of osteogenic cells were conducted on the CaP ceramic (i.e., the material post-hydrothermal analysis) which was found to be non-cytotoxic and displayed good biocompatibility when seeded with MG63 cells. Furthermore, a hot press scaffold fabrication technique was developed to produce a composite scaffold of CaP (derived from the marine alga) in a polycaprolactone (PCL) matrix. A salt leaching technique was further explored to introduce macroporosity to the structure (50–200 μm). Analysis indicated that the scaffold contained both micro/macroporosity and mechanical strength, considered necessary for bone tissue engineering applications.     

Genetics of programmed cell death in C. elegans: past, present and future

Genetic studies of the nematode Caenorhabditis elegans have defined a variety of single-gene mutations that have specific effects on programmed cell death. Analyses of the genes defined by these mutations have revealed that cell death is an active process that requires gene function in cells that die. Specific genes are required not only to cause cell death but also to protect cells from dying. Gene interaction studies have defined a genetic pathway for the execution phase of programmed cell death in C. elegans. Molecular and biochemical findings are consistent with the pathway proposed from these genetic studies and have also revealed that the protein products of certain cell-death genes interact directly. This pathway appears to be conserved among organisms as diverse as nematodes and humans. Important questions remain to be answered about programmed cell death in C. elegans. For example, how does a cell decide to die? How is cell death initiated? What are the mechanisms of action of the cell-death protector and killer genes? What genes lie downstream of the cell-death execution pathway? The conservation of the central cell-death pathway suggests that additional genetic analyses of programmed cell death in C. elegans will help answer these questions, not only for this nematode but also for other organisms, including ourselves.