Bibliothek

Notizen: Individuals suffering from classical migraine report an astonishing diversity of migraine auras. A frequently reported symptom is a visual hallucination known as fortification illusion (FI). Here we demonstrate that the typical zig-zag pattern of the FI can be reproduced using experimental data of orientation maps of the primary visual cortex (V1) assuming that a continuous excitation front propagates across V1. We put forward a model in which the cortical neurons within this excitation wave are activated sufficiently to contribute to conscious perception. It is shown that the discontinuous repetitive nature of the zig-zag pattern of the FI can reflect the specific layout of visual cortical orientation maps. Additionally, dynamic features of the FI are predicted based on our model.

Notizen: Rehabilitation of locomotion in spinal cord (s.c.) injured patients is unsatisfactory. Here we report the effects of a novel ‘Laufband (LB; treadmill) therapy’ based on ‘rules of spinal locomotion’ derived from lower vertebrates. Eighty-nine incompletely paralysed (44 chronic and 45 acute) para- and tetraplegics underwent this therapy, then were compared with 64 patients (24 chronic and 40 acute) treated conventionally. The programme consisted of daily upright walking on a motor driven LB initially with body weight support (BWS) provided by a harness and assisted limb movements by the therapists when necessary. Forty-four chronic patients with different degrees of paralysis undertook the programme for 3-20 weeks (median = 10.5), 0.5–18 years after S.C. damage. At the onset of LB therapy 33/44 patients were wheelchair-bound (no standing and/or walking without help by others) compared with 25 at completion of LB therapy, i.e. 76% had learned to walk independently, 7 patients with help. Only 1 subject did not improve. It was striking that voluntary muscle activity in the resting position was still low in several patients who had gained walking capability. Eleven patients who could already walk before LB therapy improved in speed and endurance. Of the 44 patients, six were capable of staircase walking before LB therapy compared with 34 afterwards. In order to validate the apparent superiority of LB therapy two types of comparisons were performed. In a ‘temporal’ control 12 spastic paretic patients, still wheelchair-bound after the period of postacute conventional therapy, performed LB immediately thereafter. After completion of LB therapy nine of these patients had learned to walk without help from others. In another control, two groups of chronic patients, matched in type of injury, time after injury (1 or more years) and history of previous rehabilitation (one or several periods of conventional therapy), were compared. One group underwent LB therapy (n= 29), the other conventional therapy (n= 24) for similar periods of time. From 18 wheelchair-bound patients, 14 became independent walkers after LB, but only 1/14 after conventional therapy. From 45 acute patients 92% (33/36) of those wheelchair-bound at the onset of LB therapy became independent, but only 50% (12/24) after conventional therapy (n= 40). It is noteworthy that voluntary muscle activity at rest was similar in both groups. The presumed underlying mechanisms are discussed in the light of the absence of any apparent effects in seven functionally completely paralysed paraplegic persons.

Notizen: The study was carried out to investigate the effect of azelastine on the Substance P (SP) concentration in bronchoalveolar (BAL) and nasal (NAL) lavage obtained from atopic grass pollen asthmatics and non-atopic healthy subjects. In BAL and NAL fluids there was a significant elevation in the baseline concentration of SP between asthmatics and volunteers. Allergen provocation induced a rise of SP in BAL and NAL in asthmatics, but not in volunteers. Azelastine pre-treatment resulted in a significant reduction of SP in baseline concentration of SP in BAL and NAL from asthmatics. An elevation of SP in BAL or NAL fluids after allergen provocation was not seen in asthmatics pretreated with azelastine. Azelastine did not influence the SP concentration in BAL and NAL of volunteers.

Notizen: Increasing evidence suggests involvement of integrins and CD44 isoforms in the pathogenesis of psoriasis, contributing to uncontrolled keratinocyte proliferation, neovascularization, and invasion of inflammatory cells. We have analyzed immunohistochemically in situ expression of integrins (CD29, CDw49b, CDw49c, CDw49e, CDw49f) and CD44 isoforms (CD44 standard, CD44 var/v6, CD44 v10) on frozen sections of normal and psoriatic skin (nonlesional skin, lesional skin before and along with topical calcitriol treatment). We did not observe visual changes of immunoreactivity in normal as compared to nonlesional psoriatic skin, while the staining pattern of CDw49c, CDw49f, and CD29 was severely altered in untreated lesional psoriatic skin. Most markedly, CDw49c, CDw49f, and CD29 were focally upregulated in suprapapillar epidermal compartments of lesional psoriatic skin, a staining pattern that is in accordance with the phenomenon that was described by Pinkus as ‘squirting papilla’. Additionally, an increased proportion of inflammatory and endothelial cells revealed immunoreactivity for CD44(std.) in untreated lesional psoriatic as compared to nonlesional psoriatic or normal skin. After 8 weeks of topical calcitriol treatment (15 μg/g ointment), the staining pattern for CDw49c, CDw49f and CD29 was markedly changed in epidermis of lesional psoriatic skin, reverting to the staining pattern characteristic for the nonlesional psoriatic or normal human skin, although epidermal expression of CDw49f was still upregulated and CDw49e-, CDw49f-, CD29-, and CD44(std.)- immunoreactive inflammatory and endothelial cells were still to be found in the dermal compartment.

Notizen: DivIVA from Bacillus subtilis is a bifunctional protein with distinct roles in cell division and sporulation. During vegetative growth, DivIVA regulates the activity of the MinCD complex, thus helping to direct cell division to the correct mid-cell position. DivIVA fulfils a quite different role during sporulation in B. subtilis when it directs the oriC region of the chromosome to the cell pole before asymmetric cell division. DivIVA is a 19.5 kDa protein with a large part of its structure predicted to form a tropomyosin-like α-helical coiled-coil. Here, we present a model for the quaternary structure of DivIVA, based on cryonegative stain transmission electron microscopy images. The purified protein appears as an elongated particle with lateral expansions at both ends producing a form that resembles a ‘doggy-bone’. The particle mass estimated from these images agrees with the value of 145 kDa measured by analytical ultracentrifugation suggesting 6- to 8-mers. These DivIVA oligomers serve as building blocks in the formation of higher order assemblies giving rise to strings, wires and, finally, two-dimensional lattices in a time-dependent manner.