Phantom pain reduction by low-frequency and low-intensity electromagnetic fields

Although various treatments have been presented for phantom pain, there is little proof supporting the benefits of pharmacological treatments, surgery or interventional techniques, electroconvulsive therapy, electrical nerve stimulation, far infrared ray therapy, psychological therapies, etc. Here, we report the preliminary results for phantom pain reduction by low-frequency and intensity electromagnetic fields under clinical circumstances. Our method is called as Electromagnetic-Own-Signal-Treatment (EMOST). Fifteen people with phantom limb pain participated. The patients were treated using a pre-programmed, six sessions. Pain intensity was quantified upon admission using a 0–10 verbal numerical rating scale. Most of the patients (n = 10) reported a marked reduction in the intensity of phantom limb pain. Several patients also reported about improvement in their sleep and mood quality, or a reduction in the frequency of phantom pain after the treatments. No improvements in the reduction of phantom limb pain or sleep and mood improvement were reported in the control group (n = 5). Our nonlinear electromagnetic EMOST method may be a possible therapeutic application in the reduction of phantom limb pain. Here, we also suggest that some of the possible effects of the EMOST may be achieved via the redox balance of the body and redox-related neural plasticity.     

Rac Regulates Vascular Endothelial Growth Factor Stimulated Motility

During angiogenesis endothelial cells migrate towards a chemotactic stimulus. Understanding the mechanism of endothelial cell migration is critical to the therapeutic manipulation of angiogenesis and ultimately cancer prevention. Vascular endothelial growth factor (VEGF) is a potent chemotactic stimulus of endothelial cells during angiogenesis. The endothelial cell signal transduction pathway of VEGF represents a potential target for cancer therapy, but the mechanisms of post-receptor signal transduction including the roles of rho family GTPases in regulating the cytoskeletal effects of VEGF in endothelial cells are not understood.

Here we analyze the mechanisms of cell migration in the mouse brain endothelial cell line (bEND3). Stable transfectants containing a tetracycline repressible expression vector were used to induce expression of Rac mutants. Endothelial cell haptotaxis was stimulated by constitutively active V12Rac on collagen and vitronectin coated supports, and chemotaxis was further stimulated by VEGF. Osteopontin coated supports were the most stimulatory to bEND3 haptotaxis, but VEGF was not effective in further increasing migration on osteopontin coated supports. Haptotaxis on support coated with collagen, vitronectin, and to a lesser degree osteopontin was inhibited by N17 Rac. N17 Rac expression blocked stimulation of endothelial cell chemotaxis by VEGF. As part of the chemotactic stimulation, VEGF caused a loss of actin organization at areas of cell-cell contact and increased stress fiber expression in endothelial cells which were directed towards pores in the transwell membrane. N17 Rac prevented the stimulation of cell-cell contact disruption and the stress fiber stimulation by VEGF.

These data demonstrate two pathways of regulating endothelial cell motility, one in which Rac is activated by matrix/integrin stimulation and is a crucial modulator of endothelial cell haptotaxis. The other pathway, in the presence of osteopontin, is Rac independent. VEGF stimulated chemotaxis, is critically dependent on Rac activation. Osteopontin was a potent matrix activator of motility, and perhaps one explanation for the absence of a VEGF plus osteopontin effect is that osteopontin stimulated motility was inhibitory to the Rac pathway.     

Geographic variation in plasticity in Eristalis arbustorum

To study the evolution of phenotypic plasticity in the field, six populations of the hoverfly Eristalis arbustorum were sampled along two parallel North-South transects over a maximum daily temperature gradient. Three populations were sampled per transect. Egg batches were collected and the offspring were reared in a split family set up over three different pupal temperature regimes in the laboratory to produce population reaction norms of colour pattern, pupal development time, wing length and thorax length. Wing length and colour pattern were corrected for body size. All four characters showed plasticity in response to rearing temperature and significant differences in height, slope and shape of the reaction norms were found. Only male colour pattern showed variation in reaction norms along the North-South gradient. Most other characters showed variation in reaction norms from West to East. The two populations lying in the middle of the transects were frequendy different from the others. Within the populations, significant genotype-environment interactions were frequently found for wing length and colour pattern, indicating that genetic variation for plasticity was present. The results suggest that the populations may have evolved plastic responses to suit local environmental conditions.     

On processing field and culture samples of desmids (Desmidiales,chlorophyta) for scanning electron microscopy

A procedure is outlined for preparing both field collected and laboratory grown desmid populations for scanning electron microscopy which avoids the use of the potentially hazardous chemicals glutaraldehyde and osmium tetroxide and reduces preparation time substantially. FAA is utilized both in fixation and mucilage removal, and living material can be prepared for critical point drying in as little as 90 min. Limitations of this procedure are outlined briefly and the use of SEM material in systematic studies is commented upon.     

Adaptation-dependent plasticity of rod bipolar cell axon terminal morphology in the rat retina

We chose synaptic terminals of rat rod bipolar cells as a model system to study activity-related changes in the overall morphology and the fine structure of synaptic sites. Using confocal laser scanning microscopy in conjunction with three-dimensional reconstruction and electron microscopy, we examined the effect of light and dark adaptation on axon terminals identified by protein kinase C (PKC) immunoreactivity. Rod bipolar cell axon terminals consisted of 2–3 polymorphic boutons situated close to the ganglion cell layer and a single ovoid swelling located more distally. Both components of the terminal complex showed adaptation-dependent differences in the distribution of PKC immunoreactivity and in their morphology. In light-adapted rod bipolar cell axon terminals, PKC immunoreactivity was homogeneously distributed throughout the cytoplasm, whereas terminals from dark-adapted animals showed PKC immunoreactivity preferentially localised in the submembrane compartment and a reduced staining of the more central cytoplasm. In three-dimensional reconstructions of optical sections and at the ultrastructural level, the shape of light-adapted axon terminals was round and smooth and exhibited more convexly curved synaptic membranes. In contrast, dark-adapted terminals had irregular contours, numerous dimples and a concave synaptic curvature. No spinules of bipolar cell terminals were observed in dark-adapted material. These observations are discussed in the context of activity-related morphological plasticity of central nervous system synapses and of the functions of PKC in the cycle of vesicle fusion and retrieval at the tonically active ribbon synapses of the rod bipolar axon terminal. Received: 9 April 1998 / Accepted: 23 June 1998     

X-linked ubiquitin-specific peptidase 11 increases tauopathy vulnerability in women

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