An account of the systematic error in judging what is reachable.

An account of the postural determinants of perceived reachability is proposed to explain systematic overestimations of the distance at which an object is perceived to be reachable. In this account, these errors are due to a mapping of the limits of prehensile space onto a person's perceived region of maximum stretchability, in the context of a whole-body engagement. In support of this account, 6 experiments on the judged reachability of both static and dynamic objects are reported. We tentatively conclude that the mental imagery of action is grounded and calibrated in reference to multiple skeletal degrees of behavioral freedom. Accordingly, this calibration is a source of systematic error in reachability judgments. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of nonspecific mechanisms of defense by lactic acid bacteria: effective dose.

The purpose of this study was to determine the effect of a fermented milk product containing Lactobacillus johnsonii La1 (formerly known as Lactobacillus acidophilus La1) on the phagocytic activity of peripheral blood leukocytes in healthy adult volunteers. Furthermore, we sought to define the effective doses of the bacteria, examine the effect on respiratory burst activity, and, finally, examine the contribution made by the starter culture to the biological effects. Volunteers were randomly distributed among three groups; each subject received one pot (150 ml) of fermented milk each day for 3 wk. The first two groups received a freshly prepared product fermented by Streptococcus thermophilus (group A) alone or S. thermophilus and 10(7) cfu/ml L. johnsonii La1 (group B). Group C received a product stored for a period of 21 to 28 d and that contained S. thermophilus and 10(6) cfu/ml of L. johnsonii La1. Ingestion of L. johnsonii La1 did not significantly increase fecal lactobacilli counts. However, L. johnsonii La1 was able to survive intestinal transit and was only recovered from the feces of the volunteers of groups B and C. The fermented base alone showed a weak effect on respiratory burst but not on phagocytic activity. However, the product containing 10(7) cfu/ml L. johnsonii La1 significantly enhanced both functions. The product containing 10(6) cfu/ml of L. johnsonii La1 had no significant effect on either function. These results suggest that fecal persistence may not necessarily reflect in vivo colonization and may not be a prerequisite for all forms of immune reactivity.     

End-stage cystic fibrosis: improved diabetes control 2 years after successful isolated pancreatic cell and double-lung transplantation

Over a period of years, insulin-dependent diabetes and respiratory insufficiency developed in a 35-year-old patient with end-stage cystic fibrosis. After waiting more than 4 years while receiving maintenance treatment with continuous liquid O2 and nasal ventilation, the patient underwent double-lung and pancreatic islet cell transplantation. Subsequently, the patient has enjoyed a normal life with full employment and much better control of his diabetes. Pancreatic islet cell transplantation is a simple and innocuous technique easily added to the end of lung transplantation. These new pancreatic cells, although locally injected, are still secreting more than 2 years later as assessed by repeated C-peptide measurements.     

Durability of aminosilane-silica hybrid gas-barrier coatings on polymers

Aminosilane solutions with pH equal to 8 and to 11 were applied and cured on SiO₂-coated poly(ethylene terephthalate) (PET) films. The permeability of the silane-silica hybrid coating on PET was reduced twofold compared to that of the SiO₂/PET film, at solution concentrations as low as 1 wt.%, irrespective of the pH. This concentration level led to a dense silane monolayer crosslinked to the silica surface. The oxygen transport mechanisms in the hybrid coatings were determined based on the thermally activated rate theory. Permeation experiments were also performed under tensile loading, and the critical strain for loss of barrier performance was found to be improved by a factor of two, only in case of basic pH. The defect population and morphology of the hybrid coating subjected to hydrothermal aging were analyzed using a reactive ion etching method and atomic force microscopy, respectively. These experiments confirmed the defect healing action of the aminosilane at low concentrations in solution, through the formation of a densely crosslinked polysiloxane layer at the silane-silica interface for both pH8 and pH11. The influence of the silane treatment was emphasized in case of basic pH due to the dissolution of superficial oxide layers.     

beta-Endorphin and blood pressure in multiple trauma victims

In addition to pain and stress, endogenous opiates and in particular beta-endorphin could be involved in the modulation of cardiovascular parameters. Several studies have thus shown increases in plasma beta-endorphin levels in the course of septic or hypovolemic shock. Our study involving 44 multiple trauma patients indicates that even in the absence of any hemodynamic disorders, there is a correlation between systolic blood pressure and plasma beta-endorphins. These results argue in favor of the existence of feedback between systolic blood pressure and plasma beta-endorphins.     

Synthesis and characterization of leiurotoxin I analogs lacking one disulfide bridge: evidence that disulfide pairing 3-21 is not required for full toxin activity

Leiurotoxin I (Lei-NH2), a toxin isolated from the venom of the scorpion Leiurus quinquestriatus hebraeus, is a blocker of the apamin-sensitive Ca(2+)-activated K+ channels. It is a 31-residue polypeptide cross-linked by three disulfide bridges which are presumably between Cys3-Cys21, Cys8-Cys26, and Cys12-Cys28. To investigate the role of these disulfides, analogs of Lei-NH2 lacking one disulfide bridge (i.e., [Abu3,21]Lei-NH2, [Abu8,26]Lei-NH2, and [Abu12,28]Lei-NH2) were chemically synthesized by selective replacement of each pair of half-cystines forming a bridge by two alpha-aminobutyrate (Abu) residues. The two disulfide pairings of the main folded form of the synthetic analogs were established by enzymatic proteolysis. They were as expected between Cys8-Cys26 and Cys12-Cys28 for [Abu3,21]Lei-NH2 but were unexpectedly between Cys3-Cys12 and Cys21-Cys28 for [Abu8,26]Lei-NH2 and between Cys3-Cys8 and Cys21-Cys26 for [Abu12,28]Lei-NH2. The synthetic peptides were tested in vitro for their capacity to compete with the binding of [125I]apamin to rat brain synaptosomes and in vivo for their neurotoxicity in mice. In both assays, [Abu3,21]Lei-NH2 exhibited full Lei-NH2-like activity whereas [Abu8,26]Lei-NH2 and [Abu12,28]-Lei-NH2 possessed only residual activities (< 2% native toxin activity). This suggests that disulfide bridge Cys3-Cys21 is not essential per se for high toxin activity. Circular dichroism (CD) spectroscopy of the three analogs showed that only [Abu3,21]Lei-NH2 exhibited a CD spectrum similar to that of Lei-NH2, suggesting they both adopt closely related conformations, in agreement with the pharmacological data. Structural models of the analogs were constructed on the basis of the disulfide pairing assignment and compared with that of Lei-NH2.     

Amino acid sequences of neurotoxins I and III of the elapidae snake Naja mossambica massambica

The amino acid sequences of two neurotoxins of the African cobra Naja mossambica mossambica have been determined using almost uniquely phenylisothiocyanate degradation in a liquid protein sequencer programmed alternatively with 'protein' and 'peptide' programs. When compared to known sequences of so-called 'short' neurotoxins belonging to other Elapidae snakes, neurotoxins I and III of Naja mossambica mossambica are very similar to the cobrotoxin, a neurotoxin isolated from the formosan cobra Naja atra atra.