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E Vögelin

Publications and source records attributed to E Vögelin.

16 recordsLinked to original sources
PubMed2006

Effects of local continuous release of brain derived neurotrophic factor (BDNF) on peripheral nerve regeneration in a rat model.

The purpose of this study was to evaluate the effect of continuously released BDNF on peripheral nerve regeneration in a rat model. Initial in vitro evaluation of calcium alginate prolonged-release-capsules (PRC) proved a consistent release of BDNF for a minimum of 8 weeks. In vivo, a worst case scenario was created by surgical removal of a 20-mm section of the sciatic nerve of the rat. Twenty-four autologous fascia tubes were filled with calcium alginate spheres and sutured to the epineurium of both nerve ends. The animals were divided into 3 groups. In group 1, the fascial tube contained plain calcium alginate spheres. In groups 2 and 3, the fascial tube contained calcium alginate spheres with BDNF alone or BDNF stabilized with bovine serum albumin, respectively. The autocannibalization of the operated extremity was clinically assessed and documented in 12 additional rats. The regeneration was evaluated histologically at 4 weeks and 10 weeks in a blinded manner. The length of nerve fibers and the numbers of axons formed in the tube was measured. Over a 10-week period, axons have grown significantly faster in groups 2 and 3 with continuously released BDNF compared to the control. The rats treated with BDNF (groups 2 and 3) demonstrated significantly less autocannibalization than the control group (group 1). These results suggest that BDNF may not only stimulate faster peripheral nerve regeneration provided there is an ideal, biodegradable continuous delivery system but that it significantly reduces the neuropathic pain in the rat model.

Animals↗
PubMed2005

The secreted brain-derived neurotrophic factor precursor pro-BDNF binds to TrkB and p75NTR but not to TrkA or TrkC.

The neurotrophin brain-derived neurotrophic factor (BDNF) binds to two cell surface receptors: TrkB receptors that promote neuronal survival and differentiation and p75NTR that induces apoptosis or survival. BDNF, as well as the other members of the neurotrophin family, is synthesized as a larger precursor, pro-BDNF, which undergoes posttranslational modifications and proteolytic processing by furin or related proteases. Both mature neurotrophins and uncleaved proneurotrophins are secreted from cells. The bioactivities of proneurotrophins could differ from those of mature, cleaved neurotrophins; therefore, we wanted to test whether pro-BDNF would differ from mature BDNF in its neurotrophin receptor binding and activation. A furin-resistant pro-BDNF, secreted from COS-7 cells, bound to TrkB-Fc and p75NTR-Fc, but not to TrkA-Fc or TrkC-Fc. Likewise, pro-BDNF elicited prototypical TrkB responses in biological assays, such as TrkB tyrosine phosphorylation, activation of ERK1/2, and neurite outgrowth. Moreover, mutation of the R103 residue of pro-BDNF abrogated its binding to TrkB-Fc but not to p75NTR-Fc. Taken together, these data indicate that pro-BDNF binds to and activates TrkB and could be involved in TrkB-mediated neurotrophic activity in vivo.

Animals↗
PubMed2005

Anatomy of the proximal cutaneous perforator vessels of the gracilis muscle.

An anatomic study was performed to analyse the proximal perforator vessels of the gracilis musculocutaneous flap. Twenty-three cadaver legs preserved by the method of Thiel were carefully dissected 24h after the proximal vascular pedicle was injected with a red silicone mass. Nine additional cadaver legs were injected with ink, to visualise the skin area supplied by the proximal perforators, respectively, clarified by a modified Spalteholz technique to demonstrate the anatomic course of the perforators. A considerable variation in numbers and localisation of proximal cutaneous perforators was found. One to four perforators were seen within an area of 6 x 6 cm(2) at the entrance of the main pedicle into the proximal gracilis muscle. Their external diameter ranged from 0.5 to 1.0 mm. The ink-injections showed an oval shaped angiosome with a mean surface of 88 cm(2) at the level of the proximal gracilis pedicle. We conclude from this anatomic study, that a cutaneous flap based on the medial circumflex femoral gracilis perforators can be harvested by experienced hands bearing in mind the unpredictable perforator-anatomy.

Arteries↗
PubMed2005

Healing of a critical-sized defect in the rat femur with use of a vascularized periosteal flap, a biodegradable matrix, and bone morphogenetic protein.

BACKGROUND: The purpose of this study was to evaluate the osseous healing of a critical-sized femoral defect in a rat model with use of recombinant human bone morphogenetic protein-2 (rhBMP-2), a matrix fabricated of D,D-L,L-polylactic and hyaluronan acid (OPLA-HY), and a vascularized periosteal flap. METHODS: The carrier matrix OPLA-HY with or without rhBMP-2 was implanted in a 1-cm-long femoral defect and secured with a plate and screws. In some groups, a vascularized periosteal flap was harvested from the medial surface of the tibia. In group 1, the femoral defects in the animals were filled with the OPLA-HY matrix alone; in group 2, the OPLA-HY matrix was covered by the vascularized periosteal flap; in group 3, 20 mug of rhBMP-2 was added to the OPLA-HY matrix; and in group 4, the femoral defect containing the OPLA-HY matrix and 20 mug of rhBMP-2 was wrapped circumferentially by the vascularized periosteal flap. The presence and density of new bone formation in the femoral defect were evaluated radiographically, histologically, and with histomorphometry at four and eight weeks postoperatively. RESULTS: Groups 1 and 2, which were not treated with rhBMP-2, showed no radiographic or histologic evidence of mature bone formation at four or eight weeks. Both groups 3 and 4, which were treated with rhBMP-2, demonstrated excellent bone formation. However, with the periosteal flap, group 4 demonstrated more bone formation on histomorphometric analysis at eight weeks (43.1%) than did group 3 (28.3%) (p < 0.01). Additionally, heterotopic bone formed outside the boundaries of the defect in eight of the fifteen animals in group 3, which had no periosteal flap. CONCLUSIONS: Bone-tissue engineering with use of the OPLA-HY matrix and rhBMP-2 produced good bone formation in the rat femoral defect model. However, the addition of a vascularized periosteal flap significantly increased bone formation within the boundaries of the defect and prevented heterotopic ossification.

Animals↗
PubMed2002

[How reliable is the posterior interosseous artery island flap? A review of 88 patients].

The distally-based, reverse posterior interosseous flap can be used to reconstruct soft-tissue defects in the region of the hand, provided there is an intact anastomotic network of the posterior and anterior interosseous system at the wrist. Between 1986 and 2000, 88 flap procedures were planned. Anatomical variations were recorded in 21 patients (24 %), in five of which the flap could not be harvested. In the remaining 16 patients, flap dissection was more difficult due to anatomical variations. There was a complication rate of 23 %, including haematoma, congestion, infection or technical errors, which resulted in flap necrosis of variable degrees in 11 patients (13 %). In case of haematoma, flap loss could be reduced by early revision surgery. There was no statistical correlation between anatomical variations and complications or flap loss. Secondary flap corrections, including defatting and remodelling, were commonly performed in due course. Knowing the limitations of the posterior interosseous flap, fasciocutaneous flaps are considered ideal to reconstruct soft-tissue defects or contractures of the thumb web and the dorsal hand because of good tissue matching. Fascial flaps are a good option for palmar defects or to wrap around neurolyzed nerves.

Adolescent↗
PubMed2000

[Heterotopic and orthotopic bone formation with a vascularized periosteal flap, a matrix and rh-BMP-2 (bone morphogenetic protein) in the rat model].

The purpose of this study was to construct a vascularized bone graft using the osteoinductive bone morphogenetic protein (rh-BMP-2), a polylactic acid matrix (OPLA/HY), and a vascularized periosteal flap containing osteoprogenitor cells ectopically in the groin or orthotopically in a femoral defect. In the Lewis rat, periosteal flaps were harvested from the medial surface of the tibia vascularized by the saphenous artery and vein and were transferred to the groin on its vascularized pedicle. Alternatively, the periosteal flap along its pedicle was transferred between the thigh muscles to be wrapped around a femoral defect of 1 cm. The animals were divided into 10 groups (82 animals). In group 1, the periosteal flap was left empty in the groin. Groups 2 and 3 consisted of the periosteal flap and 20 micrograms rh-BMP-2, but in group 3 the vascular pedicle was ligated proximally. In group 4 the flap was harvested without the periosteal layer and turned "inside out". Groups 5 and 6 consisted of the periosteal flap and the matrix OPLA/HY +/- 20 micrograms rh-BMP-2. In the femoral defect model, bone formation was studied using the matrix OPLA/HY alone (group 7) or combined with the vascularized periosteal flap (group 8), or in combination with OPLA/HY + BMP (group 9) or OPLA/HY + BMP + the periosteal flap (group 10). The presence and density of new bone formation in the groin and femoral defect were evaluated radiologically and histologically at 4 and 8 weeks. Good bone formation in the groin chamber (ectopic) was demonstrated in the periosteal flap + OPLA/HY + BMP group. In the femoral defects, good bone formation (orthotopic) was seen in the OPLA/HY + BMP + the periosteal flap groups. However, with the presence of a vascularized periosteal flap, more bone formation along the rim of the defect was observed. This study of ectopic bone formation in the groin and orthotopic bone formation in the femoral defect demonstrates that optimal bone formation requires four factors: BMP, a biodegradable matrix, osteoprogenitor cells, and blood supply. Potentially in the future, this technique could be used to reconstruct a bony defect or a nonunion by covering the involved area with a vascularized periosteal flap and a suitable matrix combined with BMP. Alternatively, a vascularized bone graft could be prefabricated at a distant site and then transferred microsurgically into a defect.

Animals↗
PubMed2000

Practical illustrations in tissue engineering: surgical considerations relevant to the implantation of osteoinductive devices.

This paper provides practical illustrations in the use of osteoinductive devices (biomaterial carriers coupled with osteoinductive morphogens) for bone tissue engineering. We discuss the considerations relative to the implantation of these devices that may induce tissues that are located outside the boundaries of the osteoinductive device as well as outside boundaries of the normal skeletal envelope. Five reports of osteoinductive devices generating such tissues are reviewed. Histologic and radiographic data from a sixth example are presented and compared with histologic and radiographic findings typical of two varieties of myositis ossificans. A theory is advanced that osteoinductive implants may induce ectopic tissues that resemble fibro-osseous pathologies. Finally characteristics of tissue-engineered bone graft substitutes that may contribute to development of these pathologies and device characteristics that may obviate these ectopic tissues are considered.

Animals↗
PubMed1997

Facial palsy following trauma to the external ear: 3 case reports.

We report two children and a young adult who developed unilateral facial palsy shortly after injury to the external ear. In two instances the paralysis followed a prominent ear correction and in the other a laceration to the concha. The trauma-triggered facial palsy was most likely idiopathic although the anatomy of the facial nerve near the ear leads one to speculate on a possible pathway of a virally induced palsy (Bell's palsy). Each patient recovered over a period of 6 months.

Adult↗
PubMed1997

Breast cancer in previously burned skin: a postburn skin adnexal malignancy?

An unstable postburn scar at the submammarian fold 6.5 months after a burn injury turned out to be breast cancer. The unexpected histological findings and a possible correlation between the burn and the malignancy are discussed. This care report emphasizes the importance of histopathologic examination and the chance of unusual findings in a postburn ulcer.

Adenocarcinoma↗
PubMed1996

Laser treatment for an unusual reactive vascular proliferation.

An unusual case of severe vascular proliferation presenting in the form of haemorrhaging cutaneous lesions on the leg is reported. The similarity between these benign lesions and various malignancies is outlined. The patient healed well when the lesions were excised using a laser under local anaesthetic.

Aged↗
PubMed1995

Is soft tissue expansion in lower limb reconstruction a legitimate option?

From 1986 to 1994, a consecutive series of 34 patients had 37 expanders placed in their legs. Indications for expansion included removal of painful ro unstable scars, chronic post-traumatic ulcers and one benign skin lesion. In 13 patients the lesion or scar was greater than 5 cm in diameter. The area of expansion was mainly in the proximal and distal thirds of the lower limb. On three occasions two expanders were simultaneously used in the same patient. The treatment with this technique was ultimately successful in 23 patients (67.6%) but 15 of the 23 patients (44% of the 34 patients) had minor wound healing problems. Before 1990, technical complications such as leaking injection ports caused further small interventions in 6 patients without compromising the ultimate outcome. The goal was not achieved with the expansion technique in 11 patients (32%). 5 of these 11 patients could be treated successfully with another surgical modality. All 34 patients were re-evaluated with an average follow-up of 4.5 years. We conclude that tissue expansion is ideal for removal of localised areas of scar, repair of contour defects and excision of benign tumours. Contraindications of soft tissue expansion are, in general, extensive scarred areas with compromised blood supply after trauma, vascular disease and osteomyelitis. These conditions require reconstruction with well vascularised tissue such as muscle flaps. A compliant patient is essential for lower limb reconstruction with tissue expansion. In spite of the tempting simple method of tissue expansion, success in the lower limb depends not only on the indication but also on the operating technique of the plastic surgeon.

Adolescent↗
PubMed1994

How does a pure muscle cross-leg flap survive? An unusual salvage procedure reviewed.

An exceptional indication for a cross-leg gastrocnemius flap used as a pure muscle flap in the distal third of the lower leg is presented. The vascular status of the patient after the accident and extensive colonized wounds in the injured lower leg did not favor any microvascular reconstruction. Because no cross-leg muscle flap has been mentioned in the literature so far, technical details of the procedure are explained. This case report leads to a discussion of the principles of wound healing in cross-leg muscle flaps as an example for early loss of axial blood supply. Furthermore, it adds new variety to the numerous procedures that use the gastrocnemius flap.

Adult↗