Defects in signal transduction during replicative senescence of diploid human fibroblasts in vitro

Decompression of the suprascapular nerve through the posterior approach minimizes muscular damage and postoperative scar. The difficulty with this approach is that the depth of the exposure makes operating around the delicate structures of the suprascapular artery and nerve challenging. Spine surgery instrumentation is very helpful in circumventing this problem. Once exposure is achieved, a nerve root retractor is used to retract the suprascapular artery and vein. A number 2 Woody Woodson elevator is used to protect the suprascapular nerve. A number 1 or 2 Kerrison rongeur is then used to resect the suprascapular ligament. The Kerrison rongeur is a particularly useful instrument if an ossified ligament is encountered.     

Energy-dependent accumulation of fluoroquinolones in quinolone-resistant Klebsiella pneumoniae strains

The intracellular accumulation of norfloxacin and pefloxacin in Klebsiella pneumoniae was evaluated. The roles of lipopolysaccharide, capsule, and outer membrane proteins were not important for the intrabacterial accumulation of fluoroquinolones in isogenic strains with known outer membrane alterations. In fluoroquinolone-resistant clinical isolates also expressing GyrA alterations, an active efflux leading to decreased accumulation of the drugs enhanced their resistance to these agents.     

Effect of mixed mode I and II loading on the fracture surface of polymethyl methacrylate (PMMA)

In this paper studies conducted on Polymethyl methacrylate (PMMA) under combined bending and shear loading are described. A strong dependency of fracture surface features on the mixed mode stress state is observed. Close to pure mode I, the fracture surface is mirror-like in appearance. With increasing mode II component the fracture surface becomes misty and parabolic markings appear on the fracture surface. These observations indicate that the level of stress ahead of the crack tip increases with increasing mode II component. The mixed mode specimens are also observed to fracture at much higher stresses than the pure mode I specimen, contrary to the predictions of the fracture criteria based on linear elastic fracture mechanics (LEFM). The fracture surface features and the higher stresses at fracture in the mixed mode specimens are explained in terms of the increase in stiffness (which has been related to an increase in the effective stress intensity factor per unit opening displacement) with the introduction of a mode II component and the geometry of the 3-dimensional crack tip.     

Algorithmic Decision-Making and the Control Problem

Minds and Machines - The danger of human operators devolving responsibility to machines and failing to detect cases where they fail has been recognised for many years by industrial psychologists...     

Isolation of fecal coliform bacteria from the diamondback terrapin (Malaclemys terrapin centrata)

Total and fecal coliform bacteria were isolated from the cloaca and feces of the estuarine diamondback terrapin. The majority of samples contained fecal coliforms. Escherichia coli was the predominant fecal coliform species isolated, and members of the genus Salmonella were isolated from 2 of 39 terrapins. Fecal coliform numbers are used to regulate shellfish harvests, and diamondback terrapins inhabit the brackish-water habitats where oyster beds are found; therefore, these findings have implications for the efficacy of current regulatory parameters in shellfishing waters.     

Thermodynamic Properties of Liquid Ag-Au-Sn Alloys

The thermodynamic properties of liquid Ag-Au-Sn alloys were studied with an electromotive force (EMF) method using the eutectic mixture of KCl/LiCl as a liquid electrolyte. Activities of Sn in the liquid alloys were measured at three cross-sections with constant molar ratios of Ag:Au = 2:1, 1:1, and 1:2 with tin in the concentration range between 20 at.% and 90 at.% from the liquidus of the samples up to 1030 K. The integral Gibbs energies at 973 K and the integral enthalpies were calculated by Gibbs–Duhem integration.     

Warfarin anticoagulation in the perioperative period: is it safe?

A useful correlation between maximum thyroid uptake and radioiodine urine levels at different times after exposure was developed in order to determine when the intervention with an adequate blocking agent might still be effective. In an animal model (dog), six different doses were administered in the range of 100-600 kBq. The best correlation was found between the 125I uptake after 48 h (T-48) and urine radioactivity 4-6 h (U-4, U-5, U-6) after exposure. For the case of U-4, the equation Y(T-48) = 0.790 X(U-4) + 2.973 (r = 0.974 with a level of significance of p < 0.001) was obtained. An analogous study, carried out in humans (n = 20) to whom 1311 was administered, showed a similar correlation and level of significance: Y(T-24) = 1.162 X(U-4)+3.263 (r = 0.926; p < 0.001). The validity of this correlation was confirmed in four volunteers who received small doses of 125I(25-100 kBq), with good agreement between measured and extrapolated thyroid uptake and a mean difference of less than 10% (CV = 16.2%). Three different blocking agents were then tested in the same dog: potassium iodide, potassium perchlorate, and a thionamide (Tapazole). The blocking action of the first two compounds was about 90%, as opposed to only 48% for the third compound. Potassium iodide was chosen for its limited side effects and more universal utilization. The final study, carried out with four different doses, indicated that 25 mg of KI is the ideal amount to be administered to the dog. This corresponds to approximately 100 mg for a 70 kg human being (i.e., 1.4 mg kg(-1)). This dose, when administered to a volunteer 4 h after exposure, provided a thyroid blocking of 68%.     

Enzyme activity of macrophage migration inhibitory factor toward oxidized catecholamines

Macrophage migration inhibitory factor (MIF) is a relatively small, 12.5-kDa protein that is structurally related to some isomerases and for which multiple immune and catalytic roles have been proposed. MIF is widely expressed in tissues with particularly high levels in neural tissues. Here we show that MIF is able to catalyze the conversion of 3,4-dihydroxyphenylaminechrome and norepinephrinechrome, toxic quinone products of the neurotransmitter catecholamines 3,4-dihydroxyphenylamine and norepinephrine, to indoledihydroxy derivatives that may serve as precursors to neuromelanin. This raises the possibility that MIF participates in a detoxification pathway for catecholamine products and could therefore have a protective role in neural tissues, which as in Parkinson's disease, may be subject to catecholamine-related cell death.     

Abnormalities in the p34cdc2-related PITSLRE protein kinase gene complex (CDC2L) on chromosome band 1p36 in melanoma

Recently, several clusters of hepatitis A have been observed among hemophiliacs linked to factor VIII concentrates treated for virus inactivation solely with the solvent/detergent (S/D) method, a procedure that does not affect nonenveloped viruses such as the hepatitis A virus (HAV). A new outbreak of hepatitis A in six hemophiliacs treated with the same lot of a factor VIII preparation occurred recently in Germany. The objective of the study was to clarify whether these diseases were caused by the administration of the S/D-treated plasma product, rather than a community-acquired infection. Polymerase chain reactions designed to detect HAV nucleic acid have been carried out in the implicated factor VIII lots, in the corresponding plasma pools, and in serum samples of four out of six infected individuals. The nucleic acid sequences were determined in samples that resulted in positive amplification products. HAV sequences were found in one of the two plasma pools used for manufacture of the incriminated product, in the incriminated lot itself, and in all recipient sera tested so far, although the latter were collected up to 7 weeks after the onset of jaundice. The sequences obtained were completely identical, revealing a unique HAV strain of genotype IA. This study provides conclusive evidence that hepatitis A can be transmitted by factor VIII concentrates treated solely by the S/D procedure for virus inactivation. This inactivation method is not effective against nonenveloped viruses. Since a number of hepatitis A transmission episodes have been described with such preparations during the past 10 years, their continued use seems to be questionable unless additional virus removal or inactivation steps are introduced to prevent the transmission of nonenveloped viruses. Molecular approaches again proved to be reliable tools for elucidating the chain of virus transmission.     

Views of TAGSI on the effects of gamma irradiation on the mechanical properties of irradiated ferritic steel reactor pressure vessels

The paper reviews and analyses the effects of gamma irradiation dose on the properties of ferritic steels used in reactor pressure vessels (RPVs). It explains factors that affect the embrittlement of a RPV steel induced by combinations of fast neutrons, thermal neutrons, and gamma irradiation.

TAGSI were asked to consider the effects of gamma irradiation dose on the properties of steels used in reactor pressure vessels. TAGSI endorsed the use of the MCBEND code to calculate gamma fluxes and energetic gamma ray displacement cross-sections calculated using either Baumann or Alexander methods. TAGSI endorsed the calculation of the materials property changes due to an additional gamma dose using trend curves based on empirical correlation to neutron-induced damage (where k_γ1±0.25).