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Background: Limited experimental research has been performed on the treatment of avascular necrosis (AVN) by vascularized bone grafting., Questions/purposes: A new model simulating carpal AVN was created to investigate surgical revascularization of necrotic bone., Methods: In seven mongrel dogs, AVN was induced by removal of the radial carpal bones bilaterally, deep-freezing, coating in cyanoacrylate, and reimplantation. A reverse-flow vascularized bone graft from the distal radius was implanted in the avascular radial carpal bone. The contralateral side served as an untreated ischemic control. Bone blood flow, bone volume, radiography, histomorphometry, histology, and MRI were analyzed at 4 weeks., Results: Blood flow was substantially higher in grafted bones when compared with controls (14.68 ± 15.43 versus 0.27 ± 0.28 mL/minute/100 g). Blood flow correlated with increased osteoid formation and higher levels of bone turnover. T1 and T2 signals on MRI did not correlate with quantitative bone blood flow measurements. Necrotic bones with no blood flow had normal T1 and T2 signals, whereas revascularized bones had signal changes when compared with adjacent carpal bones. No major collapse occurred in any radiocarpal bone., Conclusion: In a canine experimental model, investigation of carpal AVN shows the ability of vascularized bone grafting to revascularize and remodel avascular bone., Clinical Relevance: Surgical revascularization of necrotic bone induced by vascularized bone grafting results in increased bone perfusion and bone remodeling as compared with untreated necrotic bone. MRI T1 and T2 signals can be normal in necrotic avascular bone.

Acetic acid is a traditional antiseptic agent that has been used for more than 6000 years. The main goal of this study was to demonstrate the suitability of Suprathel (PolyMedics Innovations GmbH, Denkendorf, Germany) in combination with various antiseptic agents to create an "antiseptic-matrix" especially designed for problematic microorganisms such as Proteus vulgaris, Acinetobacter baumannii, or Pseudomonas aeruginosa, which are frequently associated with burns. The study was designed to test the in vitro antimicrobial effect of a "Suprathel-antiseptic matrix" (Suprathel combined with acetic acid 3%, povidone-iodine 11% [Betaisodona], polyhexanide 0.04% [Lavasept], phenoxyethanol 2%/octenidine dihydrochloride 0.1% [Octenisept], mafenide acetate 5%, and chlorhexidine gluconate 1.5%/cetrimid 15% [Hibicet]). As a means to assess the typical bacterial spectrum of a burn unit, the following Gram-negative and Gram-positive bacteria strains were tested: Escherichia coli, P vulgaris, P aeruginosa, A baumannii, Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus, methicillin-resistant S aureus, and β-hemolytic streptococcus groups A and B. The tests showed a positive bactericidal effect of the Suprathel-antiseptic matrix, particularly with problematic Gram-negative bacteria such as P vulgaris, P aeruginosa, and A baumannii, except for the combination of Suprathel and mafenide acetate. It can be concluded that Suprathel-antiseptic matrix appears to be suitable as a local antiseptic agent, but clinical studies need to be performed to confirm these in vitro observations. The authors' previous studies have shown that acetic acid demonstrates a wide antiseptic spectrum for microorganisms typically found in burn patients. The combination of Suprathel and acetic acid worked well in this study and appears to be promising for future clinical application.

Purpose: Perilunate injuries cause severe carpal malalignment. Open reduction and internal fixation of these injuries has become the treatment of choice. This study evaluated clinical outcome and the patients' perception of disability in activities of daily living after open reduction, ligament reconstruction, and/or internal fixation of the scaphoid. In addition, potential prognostic factors for functional outcome and individual perceptions of disability were analyzed and compared with radiologic findings., Methods: This study consisted of a retrospective analysis of patients with perilunate dislocations or fracture dislocations (Mayfield stage 3/4) who were treated in a single institution from 1995 to 2004. Evaluation focused on postoperative radiologic results, range of motion, pain, sensitivity, grip strength, Mayo and Krimmer wrist scores, arthrosis, and the patients' disability in performing activities of daily living (according to the Disabilities of the Arm, Shoulder, and Hand score)., Results: Of the 72 patients treated in the study period, 39 patients (all men) were available for complete follow-up (average, 65.5 mo). Thirty injuries were fracture dislocations; the dominant hand was injured in 14 cases. Normal scapholunate (SL) angles and Gilula arcs were achieved intraoperatively in 34 and 25 cases, respectively. At follow-up, 18 patients had larger than normal SL angles, and 6 patients had ulnar shifting of the carpus. Twenty patients were diagnosed with radiocarpal arthrosis. According to the Visual Analog Scale, pain was 1.8 at rest and 4.8 with activities. Average extension/flexion was 77°; radial/ulnar abduction was reduced to 42°. Average grip strength was reduced to an average of 36.6 kg (compared with 51.6 kg on the opposite side). Twenty-seven patients returned to their former occupations. Average Mayo and Krimmer wrist scores were both 70. The average Disabilities of the Arm, Shoulder, and Hand score was 23., Conclusions: Satisfactory results can be achieved with open reduction for perilunate injuries. However, despite this treatment, loss of reduction and arthrosis are frequent findings. Radiologic results do not necessarily correlate with functional outcome; high patient satisfaction was observed in this study., Type of Study/level of Evidence: Therapeutic IV., (Copyright © 2010. Published by Elsevier Inc.)

Mice deficient for the neuronal glycine transporter subtype 2 (GlyT2) die during the second postnatal week after developing neuromotor deficiencies, which resembles severe forms of human hyperekplexia. This phenotype has been attributed to a dramatic reduction in glycinergic neurotransmission. In the present study we analyzed the development of GABAergic and glycinergic synaptic transmission in GlyT2-knockout mice during early postnatal life. Anti-glycine immunohistochemistry in spinal cord and brainstem slices and whole-cell voltage-clamp recordings of glycinergic inhibitory postsynaptic currents (IPSCs) from hypoglossal motoneurons revealed strikingly reduced levels of synaptic glycine already at birth. Since GABA and glycine use the same vesicular inhibitory amino acid transporter (VIAAT or VGAT) we also analysed GABAergic neurotransmission. No increase of GABA immunoreactivity was observed in the spinal cord and brainstem of GlyT2(-/-) mice at any stage of postnatal development. Correspondingly no up-regulation of GABAergic IPSCs was detected in GlyT2(-/-) hypoglossal motoneurons. These data suggest that in the first postnatal week, loss of the glycine transporter 2 is neither compensated by glycine de-novo synthesis nor by up-regulation of the GABAergic transmission in GlyT2(-/-) mice.

Oxidative stress after burn injuries leads to systemic capillary leakage and leukocyte activation. This study evaluates whether antioxidative treatment with high-dose vitamin C leads to burn edema reduction and prevention of leukocyte activation after burn plasma transfer. Donor rats underwent a burn (n = 7; 100 degrees C water, 12 seconds, 30% body surface area) or sham burn (37 degrees C water; n = 2) procedure and were killed after 4 hours for plasma harvest. This plasma was administered to study rats (continuous infusion). Rats were randomized to four groups (n = 8 each; burn plasma alone [BP]; burn plasma/vitamin C-bolus 66 mg/kg and maintenance dose 33 mg/kg/hr [VC66]; burn plasma/vitamin C-bolus 33 mg/kg and maintenance dose 17.5 mg/kg/hr [VC33]; and sham burn plasma [SB]). Intravital fluorescence microscopy in the mesentery was performed at 0, 60, and 120 minutes for microhemodynamic parameters, leukocyte adherence, and fluorescein isothiocyanate-albumin extravasation. No differences were observed in microhemodynamics at any time. Burn plasma induced capillary leakage, which was significantly higher compared with sham burn controls (P < .001). VC66 treatment reduced microvascular barrier dysfunction to sham burn levels, whereas VC33 had no significant effect. Leukocyte sticking increased after burn plasma infusion, which was not found for sham burn. Vitamin C treatment did not influence leukocyte activation (P > .05). Burn plasma transfer leads to systemic capillary leakage. High-dose vitamin C treatment (bolus 66 mg/kg and maintenance dose 33 mg/kg/hr) reduces endothelial damage to sham burn levels, whereas half the dose is inefficient. Leukocyte activation is not influenced by antioxidative treatment. Therefore, capillary leakage seems to be independent from leukocyte-endothelial interactions after burn plasma transfer. High-dose vitamin C should be considered for parenteral treatment in every burn patient.

Background: Large segmental osseous defects are challenging clinical problems. Current reconstructive methods, using non-viable allografts, vascularized autografts or prostheses have significant rates of serious complications and failure. These include infection, stress fracture and non-union (frozen structural allogenic bone); loosening and implant failure (prosthetic replacement); limited availability, poor match of size and shape and donor site morbidity (vascularized autograft bone). In the future, microvascular transplantation of living allogenic or xenogenic bone could solve some of these issues, combining the advantages of living bone autografts (capability of primary osseous healing, remodeling, and fracture resistance) with the ability to match size and shape, provide immediate stability and avoid donor site morbidity. Xenotransplants would be particularly attractive, as they could be readily available, if long-term bone survival could be achieved without unacceptable morbidity. Here, we present a preliminary study to evaluate a new and unique method to maintain xenogenic bone circulation without need for long-term immune modulation that depends upon generation of a neo-angiogenic circulation within the transplanted bone from recipient-derived vessels. Thus, only short-term immunosuppression would be required to achieve bone survival., Methods: One hundred and forty-one hamster femora were microsurgically transplanted to rats, restoring nutrient vessel circulation with standard microvascular anastomoses. At the same time, a host-derived arteriovenous bundle (AVB) was placed within the medullary canal. Two independent variables were evaluated: use of tacrolimus/cyclophosmamid immunosuppression (IS) and patency of the implanted AVB. Rats were therefore randomized to four groups; group 1-no IS + patent AVB; group 2-no IS + ligated AVB; group 3-IS + patent AVB; group 4-IS + ligated AVB. Rats were sacrificed after 1 or 2 weeks. We evaluated bone blood flow (microsphere entrapment), neoangiogenesis (microangiography and quantification of capillary density), bone necrosis rate (osteocyte counts) and nutrient pedicle rejection (microsurgical anastomotic patency). Statistical Analysis was performed with two-way ANOVA with Bonferroni adjustment. Differences were considered significant when P < 0.05., Results: Capillary density was significantly increased with a patent intramedullary AVB (groups 1/3) compared to groups with ligated AVBs (groups 3/4). Capillary sprouting was predominantly restricted to the endosteal layer. Most nutrient pedicles (78.7%) stayed patent in groups with IS (groups 3 and 4). Consequently, bone blood flow was significantly higher in groups 3 and 4 compared to groups 1 and 2. Similarly, a patent AV bundle improved flow in group 1 when compared to group 2. The bone necrosis rate was not influenced by the presence of patent AVBs but was significantly reduced in groups 3 and 4., Conclusions: Surgical angiogenesis occurs when patent arteriovenous bundles are placed in the medullary canal of xenogenic bone and leads to increased bone blood flow. Bone viability was not significantly influenced by neoangiogenesis. Although capillary sprouting was restricted to the endosteal layer in this short term study, more complete cortical revascularization might be observed in a long-term study. Such a study should further evaluate whether these new vessels supply sufficient blood flow to maintain long-term bone viability and allow remodeling.

Thermal injuries of more than 20% body surface area (BSA) result in systemic capillary leakage with subsequent edema. This can similarly be induced by burn plasma transfer (BPT) from burned individuals to healthy rats. We evaluated if cerium nitrate (CN) bathing can prevent edema after BPT. Therefore, donor rats (DR) underwent thermal injury (100 degrees C water, 30%BSA, 12 s) for positive controls and were additionally bathed in CN (0.05M, at 10 and 120 min) for study groups. For negative controls DR underwent shamburn (37 degrees C water, 30%BSA, 12 s). DR-plasma (harvested 4 h post trauma) was transferred to healthy individuals. Intravital microscopy was performed in mesenteric venules (0/60/120 min). Edema was assessed by FITC-albumin extravasation. Additionally, leukocyte sticking (cells/mm(2)) and micro hemodynamic parameters were assessed. Significant systemic capillary leakage was observed after BPT at 120 min. Edema formation was significantly lower in negative controls. Topical CN application after 10 and 120 min reduced FITC-efflux to baseline levels. Adherent leukocytes increased slightly in all groups. Leukocyte-sticking tended to be reduced after CN bathing. In conclusion, BPT induces burn edema in healthy individuals. CN bathing after 10 and 120 min reduces mediator levels in burned individuals. Therefore, BPT after CN application does not induce burn shock anymore. Burn edema is partially independent from leukocyte activation because CN significantly influences macromolecular leakage whereas leukocyte activation is not significantly altered.

Presynaptic nerve terminals pass through distinct stages of maturation after their initial assembly. Here we show that the postsynaptic cell adhesion molecule Neuroligin1 regulates key steps of presynaptic maturation. Presynaptic terminals from Neuroligin1-knockout mice remain structurally and functionally immature with respect to active zone stability and synaptic vesicle pool size, as analyzed in cultured hippocampal neurons. Conversely, overexpression of Neuroligin1 in immature neurons, that is within the first 5 days after plating, induced the formation of presynaptic boutons that had hallmarks of mature boutons. In particular, Neuroligin1 enhanced the size of the pool of recycling synaptic vesicles, the rate of synaptic vesicle exocytosis, the fraction of boutons responding to depolarization, as well as the responsiveness of the presynaptic release machinery to phorbol ester stimulation. Moreover, Neuroligin1 induced the formation of active zones that remained stable in the absence of F-actin, another hallmark of advanced maturation. Acquisition of F-actin independence of the active zone marker Bassoon during culture development or induced via overexpression of Neuroligin1 was activity-dependent. The extracellular domain of Neuroligin1 was sufficient to induce assembly of functional presynaptic terminals, while the intracellular domain was required for terminal maturation. These data show that induction of presynaptic terminal assembly and maturation involve mechanistically distinct actions of Neuroligins, and that Neuroligin1 is essential for presynaptic terminal maturation.

Synapses can be considered chemical machines, which are optimized for fast and repeated exocytosis of neurotransmitters from presynaptic nerve terminals and the reliable electrical or chemical transduction of neurotransmitter binding to the appropriate receptors in the postsynaptic membrane. Therefore, synapses share a common repertoire of proteins like, e.g., the release machinery and certain cell adhesion molecules. This basic repertoire must be extended in order to generate specificity of neurotransmission and allow plastic changes, which are considered the basis of developmental and/or learning processes. Here, we focus on these complementary molecules located in the presynaptic terminal and postsynaptic membrane specializations of glycinergic synapses. Moreover, as specificity of neurotransmission in this system is established by the specific binding of the neurotransmitter to its receptor, we review the molecular properties of glycine receptor subunits and their assembly into functional glycine receptors with different functional characteristics. The past years have revealed that the molecular machinery underlying inhibitory and especially glycinergic postsynaptic membrane specializations is more complex and dynamic than previously anticipated from morphological studies. The emerging features include structural components as well as signaling modules, which could confer the plasticity required for the proper function of distinct motor and sensory functions.

Thermal injuries greater than 20% body surface area (BSA) result in systemic shock with generalized edema in addition to local tissue destruction. Burn shock is induced by a variety of mediators, mainly immunomodulative cytokines. This experimental study evaluates if burn shock can be induced in healthy rats by transfer of burn plasma (BP) with mediators. Thermal injury was induced by hot water (100 degrees C water, 12 s, 30% BSA) in male syngenic Wistar rats. Donor rats were killed 4 h posttrauma, and BP was harvested. Burn plasma was transferred to healthy animals by continuous intravenous infusion in three types of dilution (100%, 10%, and 1%). Positive controls were directly examined 4 h after thermal injury, and negative control rats had a continuous infusion done with sham burn (SB) plasma (37 degrees C water, 12 s, 30% BSA). Afterwards, intravital fluorescence microscopy was performed in postcapillary mesenteric venules at 0, 60, and 120 min. Edema formation was assessed by relative changes over time in fluorescence intensity of fluorescein isothiocyanate-albumin in the intravascular versus the extravascular space. The interactions of leucocytes and endothelium were evaluated by quantification of leukocyte sticking. Additionally, microhemodynamic (volumetric blood flow, erythrocyte velocity, venular wall shear rate, venular diameters) and macrohemodynamic parameters (blood pressure, heart frequency, temperature) were assessed online (arterial catheter). For statistics, an ANOVA was performed with Bonferroni adjustment procedure. Differences were considered significant when P < 0.05. There are no statistically significant differences in microhemodynamics or macrohemodynamics between study groups. Burn plasma infusion and thermal injury lead to significant increases in fluorescein isothiocyanate-albumin extravasation, whereas SB plasma shows no significant changes. Even BP diluted in 0.9% saline (10% and 1%) results in a similar transvascular flux of plasma proteins as direct thermal injury. Differences between positive controls and BP infusion are not significant, whereas all groups are statistically different from the SB group (P<0.05). Leukocyte sticking is significantly increased in all groups except the SB group, and the number of adherent leukocytes is dose dependent. The present study demonstrates that as early as 4 h after thermal injury, there are sufficient factors (e.g., cytokines) in BP to induce systemic burn shock in healthy rats even in diluted plasma (1%). However, the "key" cytokines are not identified at this point. The burned tissue is no longer required for burn shock induction, and the pathophysiologic process seems to be self-perpetuating as early as 4 h posttrauma. Leukocytes are activated by thermal injury and BP infusion. The role of leukocyte-endothelium interactions for edema formation remains uncertain and requires further investigation.

Proximal row carpectomy is a movement-preserving procedure in the treatment of arthrosis of the wrist. We have retrospectively assessed the objective and subjective functional results after proximal row carpectomy. Assessment of outcome included measurement of range of movement (ROM), grip strength and self-assessment of pain relief with a visual analogue scale (VAS) and the Disabilities of arm, shoulder, and hand (DASH) questionnaire. Results were graded using the Mayo and Krimmer wrist scores. Fourty-five patients (mean age 48 (30-67) years) were evaluated with a follow-up of 32 (8-115) months. Underlying conditions included: degenerative arthritis secondary to scapholunate advanced collapse deformity, or chronic scaphoid non-union (n=35), Kienbock disease stage III (n=4), chronic perilunate dislocation and fracture-dislocation (n=4), avascular necrosis of the scaphoid (n=1), and severe radiocarpal arthrosis secondary to distal radial fracture (n=1). Active ROM for wrist extension and flexion was 70 degrees and mean radial and ulnar deviation 30.8 degrees . Grip strength was 51% of the unaffected side. The average DASH score was 26. The intensity of the pain, measured by VAS, was reduced by 44% after strenuous activities and by 71% at rest. The Mayo and Krimmer wrist scores were 55 and 62 points indicating good results; 32 patients returned to work and 25 patients to their former occupation. Our results show that proximal row carpectomy is a technically easy operation that preserves a satisfying ROM and pain relief, and is recommended when the head of the capitate and the lunate fossa are not affected by arthrosis.

Presynaptic nerve terminals contain scaffolding proteins that orchestrate neurotransmitter release at active zones. Here we describe mover, a yet unknown non-transmembrane protein that is targeted to presynaptic terminals when overexpressed in cultured neurons. Confocal immunomicroscopy revealed that mover colocalizes with presynaptic markers in the calyx of Held. In the hippocampus, mover localizes to mossy fibre terminals, but is absent from inhibitory nerve terminals. By contrast, mover localizes to inhibitory terminals throughout the cerebellar cortex. Our results suggest that mover may act in concert with generally expressed scaffolding proteins in distinct sets of presynaptic terminals.

Background: Complex defects of the forearm and hand often require microvascular reconstruction with osteocutaneous free flaps for limb salvage., Methods: Fifteen patients with osseous and soft-tissue defects of the forearm and hand were treated with osteocutaneous flaps (1992 to 2004) and evaluated for postoperative results. Assessment focused on range of motion, pain, grip strength, and Disabilities of Arm, Shoulder, and Hand questionnaire score. Donor- and recipient-site morbidity was documented., Results: The defects resulted from trauma, infection, or malignancy. Reconstruction was possible by microvascular osteoseptocutaneous fibula transplantation (n = 8), osteocutaneous scapular or parascapular flaps(n = 6), and osteocutaneous lateral arm flap (n = 1). The average patient age was 38 years. The median osseous defect was 11.7 cm, and all patients needed additional soft-tissue reconstruction. All defects could be reconstructed in a one-step procedure after serial débridement or oncologic resection. Patients' hand function was markedly reduced compared with the unaffected extremity, but functional results were still satisfactory, with a mean Disabilities of Arm, Shoulder, and Hand score of 25.3 reflecting a moderate disability in activities of daily living. Two patients developed pseudarthrosis, and one had to undergo an ablation procedure because of persistent infection. Two patients developed wound dehiscence at the donor site, and one patient required a fasciotomy due to an imminent compartment syndrome after fibula harvest. For all patients, the functional results were acceptable when the potential alternatives were taken into consideration. This was also reflected by a high individual satisfaction rate., Conclusion: This analysis demonstrates that limb salvage with osteocutaneous free flaps is the treatment of choice for three-dimensional defects of the forearm and hand.

Herpes virus hepatitis (HSV) represents a form of acute necrotizing hepatitis, which most frequently develops in immunocompromised patients. Therapeutic options include high-dose intravenous acyclovir and liver transplantation. We report the first case of recurrent HSV hepatitis after liver retransplantation, which occurred despite continuous administration of high-dose intravenous antiviral therapy. Because explant histology pointed to initial therapy response, we thought that the reason for recurrence might be due to acyclovir resistance. Most acyclovir resistance is caused by inactivating mutations in the herpes virus thymidine kinase gene. HSV infection was detected by histology and proofed by immunohistochemistry. PCR amplification of the herpes virus thymidine kinase gene was performed on histology specimens to demonstrate the course of viral infection in liver tissue. Genotypic resistance testing of the herpes virus was performed by sequencing the thymidine kinase amplicon. In serial biopsy, HSV-DNA sequences were only detectable when histology revealed herpes hepatitis. Whereas the primary explant exhibited the wild-type thymidine kinase gene, a biopsy of the second graft one month after retransplantation, which showed recurrent herpes virus hepatitis, had a single base insertion within a homopolymeric cytosine stretch. This mutation causes a frame shift leading to a premature stop codon and results in a known acyclovir-resistant herpes strain. In conclusion, we believe that testing for acyclovir-resistant herpes strains should be considered in high-risk patients in whom viral clearance is not achieved serologically to prevent fatal recurrence of disease by using antiviral drugs such as inhibitors of HSV-DNA polymerase or viral helicase primase inhibitors.