PubMed Health⌕ Search

Biomedical subjects

H E Schaller

Publications and source records attributed to H E Schaller.

11 recordsLinked to original sources
PubMed2006

Continuous brachial plexus blockade in combination with the NMDA receptor antagonist memantine prevents phantom pain in acute traumatic upper limb amputees.

BACKGROUND: Hyperexcitability of N-methyl-d-aspartate acid (NMDA) receptors may play an important role in the development of phantom limb pain (PLP). AIM OF THE STUDY: To investigate whether early treatment with the NMDA antagonist memantine attenuates phantom pain memory formation in traumatic amputees. METHODS: In a randomized, double-blind, controlled trial 19 patients with acute traumatic amputation of the upper extremity were investigated. All patients received postoperative analgesia by continuous brachial plexus anesthesia (ropivacaine 0.375% 5 ml/h) for at least 7 days. In addition, the patients received either memantine (20-30 mg daily, n=10) or placebo (n=9) for 4 weeks. RESULTS: Memantine treatment reduced the number of requested ropivacacine bolus injections during the first week and resulted in a significant decrease of PLP prevalence and intensity at 4 weeks and 6 months follow up, but not at 12 months follow up. CONCLUSIONS: We conclude that memantine can reduce intensity of phantom limb pain and might also prevent the development of PLP. However, despite the very early begin of treatment; no long-term effect on established PLP was evident.

Adult↗
PubMed2003

Collateral arterial pathways in the forearm.

We studied the forearm vessels and the palmar carpal arch in 41 fresh cadaver upper limbs injected with colored latex solutions. In one case, we found a complete occlusion of the radial artery. Collateralization was evident through the anterior interosseous artery, its palmar branch and the radial part of the palmar carpal arch. The diameters of these vessels were significantly enlarged. The dissections of the remaining 40 arms demonstrated that these vessels offer a possible collateralization pathway via the anterior interosseous artery. One hypothesis for the formation of such collateralization might be a dominant blood flow of the radial artery to the hand. Therefore, it seems sensible to preserve the communication between the anterior interosseous and the radial arteries through the palmar carpal arch, raising the radial artery for surgery.

Arteries↗
PubMed2003

Vascular anatomy of the palmar surfaces of the distal radius and ulna: its relevance to pedicled bone grafts at the distal palmar forearm.

The potential for harvesting vascularized bone grafts from the palmar surface of the distal radius has been studied in 40 arms of fresh cadavers which had previously been injected with coloured latex solution. It was found that vascularized grafts can be pedicled on the radial part of the palmar carpal arterial arch. If a longer pedicle is required, the bone graft can be pedicled on the anterior branch of the anterior interosseous artery with retrograde flow occurring from the palmar carpal arch.

Bone Transplantation↗
PubMed2002

[Plexiform fibrohistiocytic tumour - case report of a rare low-malignant tumour with frequent localisation at the upper limb].

A male child aged nine months was admitted due to a slow growing, painless resistance at the palmar aspect of the proximal phalanx of the index finger. The intraoperative aspect of the tumour showed a yellow to white soft tissue mass with signs of infiltration. After special histopathological stainings, the diagnosis of a plexiform fibrohistiocytic tumour was confirmed. In literature almost 100 cases were reported since first description by Enzinger and Zhang in 1988. In this paper, 41 of 65 described cases showed tumour localization in the upper limb. This is the second case ever published in Germany and the first with localisation to the hand. There is very little clinical experience with this tumour entity. Local recurrence, lymphatic and pulmonal metastases with lethal outcome in rare cases are described. In the presented case, after secondary radical excision of the tumour, the patient has been free of local recurrence and actually in complete remission for 14 months.

Diagnosis, Differential↗
PubMed2002

[Evaluating scar development with objective computer-assisted viscoelastic measurement].

In a prospective study we compared the subjective scar assessment by the Vancouver Scar Scale with an objective viscoelastic measurement. Donor sites from the thigh primarily dressed with vaseline gauze (F), biobrane or occlusive dressing(O) were evaluated 0.5 years postoperatively by VSS and with the Cutometer (Courage and Khazaka). VSS of donor sites was 2.74 +/- 0.91 (F), 4.25 +/- 0.77 (B) and 2.57 +/- 0.72(O) (mean +/- sem). All ratings were significant compared to normal mirror-sided skin. Viscoelastic measurements by the Cutometer were near normal compared to uninjured skin. No correlation was found between subscale VSS pliabilty rating and Cutometer readings.

Bandages↗
PubMed2001

Multiple frequency steady-state evoked magnetic field mapping of digit representation in primary somatosensory cortex.

Magnetic source imaging of multiple frequency steady-state somatosensory evoked responses was examined using a 151-channel magnetoencephalography (MEG) system and a dual-channel electrical stimulator. Somatotopy of digit representation was studied in healthy subjects and effects of injury-related cortical plasticity in patients with unilateral transections of the median or the ulnar nerve. Dipole source locations exhibited somatotopic order with overlap between neighboring digits. In two of three nerve injury patients evidence for cortical reorganization was found. The location of sources related to digits neighboring deafferented digits was changed and their dipole moments were enlarged by comparsion with the sources related to contralateral homologue control digits. As a basis for magnetic source imaging, the recording of multiple frequency somatosensory steady-state evoked responses may be a viable and time saving alternative to the recording of transient evoked responses.

Adult↗
PubMed2000

Cortical reorganization after digit-to-hand replantation.

Functional recovery after digit-to-hand replantation depends on the interaction of various factors. In addition to peripheral mechanisms, cortical and subcortical reorganization of digit representation may play a substantial role in the recovery process. However, cortical processes during the first months after replantation are not well understood. In this 25-year-old man who had traumatically lost digits II to V (DII-V) on his right hand, the authors used magnetoencephalographic source imaging to document the recovery of somatosensory cortical responses after tactile stimulation at four sites on the replanted digits. Successful replantation of DIV and DV was accomplished at the original position of DIII and DIV with mixed innervation. Cortical evoked fields could be recorded starting from the 10th week after digit-to-hand replantation. Initially, signals from all sites showed decreased amplitudes and prolonged latencies. In the subsequent six recordings obtained between the 12th and 55th week postreplantation, a continuous increase in amplitude but only a slight recovery of latencies were observed. Components of the recorded somatosensory evoked fields were localized in the primary somatosensory cortex (SI). The localizations of the replanted DIV showed a gradual lateral-inferior shift in the somatosensory cortex over time, indicating cortical reorganization caused by altered peripheral input. The authors infer from this shift that the original cortical area of the missing finger (DII) was taken over by the replanted finger. From these data the authors conclude that magnetic source imaging might be a reliable noninvasive method to evaluate surgical nerve repair and that cortical reorganization of SI is involved in the regeneration process following peripheral nerve injury.

Adult↗
PubMed1998

[Initial muscle operations in brachial plexus paralysis].

Regeneration after surgical treatment of fresh or delayed brachial plexus injuries is often incomplete, with remaining sensory and motor loss. The aim of reconstructive surgery for these patients is to regain subordinate motor function. Therefore, reconstructive surgery should emphasize the restoration of elevation abduction and external rotation of the shoulder, elbow flexion and flexion of the fingers for basic grasping.

Arm↗
PubMed1985

DNA-binding activity is associated with purified myb proteins from AMV and E26 viruses and is temperature-sensitive for E26 ts mutants.

Oncogene protein products from avian myeloblastosis virus, p48v-myb, and from avian leukemia virus E26, p135gag-myb-ets, are located predominantly in the nucleus of nonproducer bone marrow cell clones, as revealed by indirect immunofluorescence. Both oncogene proteins were purified by immunoaffinity chromatography using monoclonal antibodies against p19 and immunoglobulins specific for myb, which was expressed in bacteria for antibody production. The purified proteins bind to DNA in vitro. In contrast, purified p135gag-myb-ets proteins from several mutants of E26 virus, temperature-sensitive for myeloblast transformation, either lost their abilities to bind to DNA or exhibited highly thermolabile DNA-protein interactions in vitro. DNA binding of AMV and E26 oncogene proteins is inhibited by myb-specific immunoglobulins. Our results suggest that lesions in the myb oncogene affect transformation as well as DNA binding of myb proteins in vitro.

Animals↗
PubMed1970

DNA synthesis in vitro.

Explore the source record for details and available documents.

Centrifugation, Density Gradient↗