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M Scheel

Publications and source records attributed to M Scheel.

15 recordsLinked to original sources
PubMed2000

Pin reduction and fixation of volar fracture fragments of distal radius fractures via the flexor carpi radialis tendon.

BACKGROUND: The objective of this study was to evaluate a technique for reduction and stabilization of residually displaced volar fragments in intraarticular distal radius fractures. METHODS: A consecutive series of patients with AO type C3 distal radius fractures treated by one surgeon were studied. Percutaneously placed pins were placed through the flexor carpi radialis tendon to reduce and stabilize volar fracture fragments of distal radius fractures when closed reduction was unsuccessful. The goal of treatment was to achieve less than 2 mm of articular congruity. Postoperative physiotherapy was protocol-based. A validated outcome measurement was used to evaluate patients. RESULTS: Of 117 patients, 10 met the inclusion criteria. In all patients, a successful reduction of the volar fragment was achieved with less than 2 mm of residual articular step-off. Reduction was maintained in 8 patients. Follow-up averaged 29 months, and there were no complications associated with the technique. All patients were satisfied with the treatment. CONCLUSION: Although the final outcome of patients with this type of fracture depends on many factors, in the small series of patients described, a satisfactory reduction was possible using the describe technique. Transtendinous pinning is a new, undescribed technique that is useful in the treatment of such specific injuries.

Adult↗
PubMed1988

Topographic organization of the auditory thalamocortical system in the albino rat.

The organization of the auditory thalamocortical connections was studied in rats. Retrograde transport of horseradish peroxidase conjugated to wheat germ agglutinin following injections into parietal, occipital and temporal cortex was used. The medial geniculate body, the suprageniculate, the lateral part of the nucleus posterior thalami, the posterior part of the nucleus lateralis thalami, and the nucleus ventroposterior project to the investigated part of the neocortex. Corresponding to different patterns of labeling, five areas of auditory neocortex were distinguished: 1. The rostral area is innervated by neurons of the nucleus ventroposterior, the lateral part of the nucleus posterior thalami, and the medial division of the medial geniculate body. 2. The dorsal area is innervated by neurons of the suprageniculate, the posterior part of the nucleus lateralis thalami and the rostral region of the dorsal division of the medial geniculate body. 3. The caudal area is innervated by neurons of the posterior part of the nucleus lateralis thalami, the suprageniculate, the medial division, the caudal region of the dorsal division and the ventrolateral nucleus of the medial geniculate body. 4. The ventral area is innervated by neurons of the suprageniculate, the medial division, the caudal region of the dorsal division, and the ventrolateral nucleus of the medial geniculate body. 5. The core area of the temporal cortex is exclusively connected to the caudal region of the medial division and the ventral division of the medial geniculate body. The findings of the present study indicate topographic organizations of the ventral division of the medial geniculate body and of the corea area. Four segments (a-d) of the ventral division each show a different set of topographic axes. They correspond to sets of topographic axes in the core area of the auditory cortex. These topographies characterize the segments which are each exclusively connected to one of the four fields of the core area.

Animals↗
PubMed1986

Morphogenesis of sclerotome and neural crest in avian embryos. In vivo and in vitro studies on the role of notochordal extracellular material.

The distribution of sclerotome and neural crest cells of avian embryos was studied by light and electron microscopy. Sclerotome cells radiated from the somites towards the notochord, to occupy the perichordal space. Neural crest cells, at least initially, also entered cell-free spaces. At the cranial somitic levels they moved chiefly dorsal to the somites, favouring the rostral part of each somite. These cells did not approach the perichordal space. More caudally (i.e. trunk levels), neural crest cells initially moved ventrally between the somites and neural tube. Adjacent to the caudal half of each somite, these cells penetrated no further than the myosclerotomal border, but opposite the rostral somite half, they were found next to the sclerotome almost as far ventrally as the notochord. However, they did not appear to enter the perichordal space, in contrast to sclerotome cells. When tested in vitro, sclerotome cells migrated towards notochords co-cultured on fibronectin-rich extracellular material, and on collagen gels. In contrast, neural crest cells avoided co-cultured notochords. This avoidance was abolished by inclusion of testicular hyaluronidase and chondroitinase ABC in the culture medium, but not by hyaluronidase from Streptomyces hyalurolyticus. The results suggest that sclerotome and neural crest mesenchyme cells have a different distribution with respect to the notochord, and that differential responses to notochordal extracellular material, possibly chondroitin sulphate proteoglycan, may be responsible for this.

Animals↗
PubMed1981

The second and third optic ganglia of the worker bee: Golgi studies of the neuronal elements in the medulla and lobula.

The gross morphology and the fine-structural characteristics of neurones of the second and third optic ganglia of the honeybee Apis mellifera were investigated light microscopically on the basis of Golgi (selective silver)- and reduced silver preparations. The second optic ganglion, the medulla, is ovoid in shape and has a slightly convex distal surface and a slightly concave proximal surface. The medullar outer levels are characteristically composed of neuronal arrangements showing strict precision of their geometrical spacing proximally as far as a pronounced layer of tangential fibre elements comprising the serpentine layer of the medulla. At the inner medullary levels retinotopic channels are again multiplied, and the arrangement of axons and dendrites contribute to a complex lattice. The third optic ganglion, the lobula, is interposed between the medulla and the protocerebrum. It is the site of termination of the third-order neurones. The lobula in hymenopterans appears, in contrast to dipterans, odonates and lepidopterans, as a single neuropilic mass. A short review of the electrophysiological data concerning these two ganglia has been tentatively correlated with some of the anatomical data.

Animals↗