Mammalian glycophosphatidylinositol anchor transfer to proteins and posttransfer deacylation

The glycophosphatidylinositol (GPI) anchors of proteins expressed on human erythrocytes and nucleated cells differ with respect to acylation of an inositol hydroxyl group, a structural feature that modulates their cleavability by PI-specific phospholipase C (PI-PLC). To determine how this GPI anchor modification is regulated, the precursor and protein-associated GPIs in two K562 cell transfectants (ATCC and .48) exhibiting alternatively PI-PLC-sensitive and resistant surface proteins were analyzed and the temporal relationship between GPI protein transfer and acquisition of PI-PLC sensitivity was determined. Nondenaturing PAGE analyses demonstrated that, whereas in .48 transfectants the GPI anchors in decay accelerating factor (DAF) and placental alkaline phosphatase (PLAP) were >95% acylated, in ATCC transfectants, they were 60 and 33% unsubstituted, respectively. In contrast, TLC analyses revealed that putative GPI donors in the two lines were identical and were >/=95% acylated. Studies of de novo DAF biosynthesis in HeLa cells bearing proteins with >90% unacylated anchors showed that within 5 min at 37 degreesC (or at 18 degreesC, which does not permit endoplasmic reticilum exit), >50% of the anchor in nascent 44-kDa proDAF protein exhibited PI-PLC sensitivity. In vitro analyses of the microsomal processing of miniPLAP, a truncated PLAP reporter protein, demonstrated that the anchor donor initially transferred to prominiPLAP was acylated and then progressively was deacylated. These findings indicate that (i) the anchor moiety that initially transfers to nascent proteins is acylated, (ii) inositol acylation in mature surface proteins is regulated via posttransfer deacylation, which in general is cell-specific but also can be protein-dependent, and (iii) deacylation occurs in the endoplasmic reticulum immediately after GPI transfer.     

Basic fibroblast growth factor (b-FGF) in the perimatrix of cholesteatoma

The growth of a cholesteatoma requires angioneogenesis in the connective tissue of the perimatrix. Angioneogenesis is also needed for wound healing as a host response to tissue injury. Normal wound repair is conducted through a wide number of growth factors. Basic fibroblast growth factor (b-FGF) plays a pivotal role in wound repair. This cytokine exerts its effects through stimulation of a wide range of target cells. B-FGF is chemotactic and mitogenic for fibroblasts, endothelial cells and keratinocytes. In addition, b-FGF can stimulate the production of collagenase and plasminogen activators to enhance fibroblast proliferation and angioneogenesis. Its necessity for normal wound repair has been confirmed by several workers. METHOD: In order to demonstrate angioneogenesis in the cholesteatoma perimatrix the distribution of b-FGF as the pivotal cytokine of the process was investigated in the perimatrix of 18 cholesteatoma specimens. RESULTS: B-FGF could be observed in 12 of 18 specimens (66%) in close approximation to histological signs of inflammation and wound healing. Areas with b-FGF also exhibited proliferation of the covering squamous epithelium. Cholesteatoma matrix tissue without inflammation or any sign of wound healing did not express b-FGF (6 of 18). CONCLUSION: Histological changes and distribution pattern of b-FGF in the perimatrix of cholesteatoma in the present study indicate that the perimatrix cells and substances of the wound healing cascade may play an important role in cholesteatoma development, angiogenesis and growth.     

The effect of electrical stimulation on colonic transit following spinal cord injury in cats

The distribution of type I collagen, the major component of human dermis, was characterized by immunohistochemistry in skin lesions of chromoblastomycosis, a chronic cutaneous mycosis, before and after a specific antifungal treatment with terbinafine to study the changes induced in the lesions by the treatment. Newly synthesized type I collagen was studied with an antibody directed against the aminoterminal propeptide of the molecule (PINP), whereas mature, cross-linked type I collagen was detected with an antibody against the carboxyterminal telopeptide of type I collagen (ICTP). The isopeptide N epsilon gamma-glutamyl lysine (N epsilon gamma GL), synthesized by transglutaminase and able to cross-link several components of the extracellular matrix, has also been investigated with two monoclonal antibodies to determine if it is involved in the stabilisation of the fibrotic cutaneous lesions. The degradative process involved in the remodelling has also been assessed by immunohistochemistry with anti-metalloproteinase (MMP-1 and MMP-9) and anti-tissue inhibitor (TIMP-1) antibodies. All tissue macrophages stained for CD68 and MMP-9, but not for MMP-1, while the polymorphonuclear neutrophils had an elastase and a weak MMP-9 phenotype. The fibroblasts of fibrotic areas stained constantly for N epsilon gamma GL and PINP. The immunostaining of extracellular matrix for ICTP and N epsilon gamma GL, and the number of PINP-positive fibroblasts, decreased significantly after one year of antifungal treatment. Terbinafine treatment decreases the synthesis of type I collagen and leads to a partial reversal of the cutaneous fibrotic lesions, independently of the cure of the fungal infection.     

2-(E)-nonen-1-ol: Male attractant for chafersAnomala vitis Fabr. andA. dubia Scop. (Coleoptera: Scarabaeidae)

Traps baited with 2-(E)-nonen-1-ol alone or in combination with other compounds caught large numbers of males of both the vine chafer,Anomala vitis Fabr. and the margined vine chafer,A. dubia Scop. (Coleoptera: Scarabaeidae), vineyard and orchard pests. In a dosage test, the largest numbers were caught by traps baited with 10 mg of 2-(E)-nonen-1-ol, which was the highest dosage tested. This is the first report on male attractants for chafer species occurring in Europe.The present paper is dedicated to the memory of our coauthor, friend and colleague Mátyás Lesznyák who died a premature and tragic death in late 1993.     

Perceptual and Psychophysiological Responses of Non-smokers to a Range of Environmental Tobacco Smoke Concentrations

Abstract To estimate the perceptual, psychophysiological and cognitive impact of environmental tobacco smoke (ETS) on non-smokers, seventeen male never-smokers, ages 21–33, were exposed to five concentrations yielding mean ETS-respirable suspended particles (RSP) levels of 58, 113, 217, 368, and 765 μg/m³. During each 90-minute session, four smokers were seated behind a partition and smoked, when cued, to generate 70-minute exposures. For control exposures, smokers “puffed” on unlit cigarettes. Odor Strength, Annoyance, Overall Acceptance and Eye Irritation at the lowest level were significantly different from control values and the degree of change generally increased monotonically with ETS level. Fatigue was not affected by any ETS level. Odor Strength (rated highest of all attributes at all levels) at the 217 μg/m³ ETS-RSP level was 12.5% of the maximum odor intensity experienced prior to the study. No effect of ETS on information processing was observed. Psychological state and eye blink rate were affected at only the 765 μg/m³ ETS-RSP level. During times when the participants were not completing a questionnaire or test, all ETS levels resulted in a 5–8% decrease in respiratory rate, due largely to an increase in expiratory duration, but no change in minute ventilation. The breathing changes may represent a psychophysiological response mediated by the olfactory system. Non-smokers are aware of ETS at ETS-RSP concentrations as low as 58 μg/m³ (?80-fold higher than the level typical of current U.S. workplace environments where smoking is permitted) but its sensory impact remains relatively small until ETS-RSP concentrations above 217 μg/m³ are encountered.     

Virtual reality (VR) for psychotherapy: From the physical to the social environment.

Discusses current and future therapeutic applications of virtual reality (VR). To date, treatments incorporating VR have involved the simulation of physical (as opposed to social) aspects of the environment. Researchers have produced simulations of heights, different kinds of spaces, and the experience of flying, with the goal of improving the delivery of exposure and desensitization for the treatment of phobias. Researchers are only beginning to explore simulation of the social environment. When VR gains the ability to simulate human social interaction, it can be used to assist in treating a wider variety of conditions, including social phobia, fear of intimacy, and sexual aversion. More long range goals are the use of VR for the exploration of childhood memories, overcoming maladaptive thinking, empowerment, increasing empathy, expressing emotions, developing and maintaining boundaries, and promoting marital satisfaction and bonding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transmission of mechanical energy through polymeric liquid crystals and their blends

Molecular composites, also called polymeric liquid crystals (PLC), are contrasted with the traditional composites; the name heterogeneous composites is proposed for the latter. Advantages of blending PLCs with ordinary engineering polymers are discussed. Results reported for blends of poly(ethylene terepthalate) (PET) with a PLC containing sequences of PET and p-hydroxybenzoic acid (PHB) include thermophysical properties, melt rheology, mechanical properties of solid blends, and scanning electron microscopy of fracture surfaces. A model called the island model was developed to explain the results: One assumes that the lines of force as well as propagating cracks tend to concentrate in the phase rich in the more flexible engineering polymer, avoiding the islands rich in the liquid-crystalline phase. This prevails until the phase inversion occurs. Predictions from the model are fully confirmed by the experimental evidence.