Effects of denosumab treatment on the expression of receptor activator of nuclear kappa-B ligand (RANKL) and TNF-receptor TNFRSF9 after total hip arthroplasty-results from a randomized placebo-controlled clinical trial.

We investigated whether the drug denosumab modulates the inflammatory response after total hip arthroplasty in a randomized controlled trial. Significantly increased expression of RANKL was found in patients treated with denosumab. This could provide an explanation for the rebound effect with rapid loss of BMD seen after discontinuation of denosumab treatment. PURPOSE: To evaluate whether denosumab, a human monoclonal antibody directed against receptor activator of nuclear factor kappa-B ligand (RANKL), modulates the inflammatory response after cementless total hip arthroplasty (THA) in patients with osteoarthritis of the hip. METHODS: Sixty-four patients operated with cementless THA were randomized to two doses of 60-mg denosumab or placebo 1-3 days and 6 months postoperatively. Serum samples were analyzed by a multiplex extension assay detecting 92 inflammation-related proteins. Bone turnover markers were assessed. Proteins were analyzed using linear mixed effect models. Validation of conspicuous findings was performed with ELISA. RESULTS: Two proteins were significantly affected by denosumab treatment: RANKL and tumor necrosis factor receptor super family member 9 (TNFRSF9). Serum levels of RANKL were more than twice as high in the denosumab than in the placebo group 3 months after surgery (ratio 2.10, p<0.001). Six and 12 months after surgery, the expression of RANKL was still elevated in the denosumab-treated group (ratios 1.50, p < 0.001; 1.47, p =0.002). The expression of TNFRSF9 was lower in the denosumab group at 3 months (ratio 0.68, p<0.001). In the denosumab group, concentrations of bone turnover markers were substantially reduced after 3 months, remained suppressed after 6 and 12 months, but increased above baseline at 24 months after surgery. CONCLUSION: Two subcutaneous denosumab injections 6 months apart increase RANKL and depress TNFRSF9 after THA. This provides a possible explanation for the rebound effect on bone turnover markers as well as bone mineral density (BMD) upon withdrawal of denosumab. None of the other measured markers of inflammation was influenced by denosumab treatment.

Antimicrobial and osteoconductive properties of two different types of titanium silver coating.

In prosthetic joint surgery, Ag coating of implant areas in direct contact with bone has been met with hesitation for fear of compromising osseointegration. The physicochemical, antibacterial and osteoconductive properties of three different Ti samples were studied: Ti6Al4V alloy that was grit-blasted (GB), Ti6Al4V alloy with an experimental Ti-Ag-nitride layer (SN) applied by physical vapour deposition (PVD) and commercially available PVD-coated Ti6Al4V alloy with a base Ag layer and a surface Ti-Ag-nitride layer (SSN, clinically known as PorAg®). Ag content on the surface of experimental SN and SSN discs was 27.7 %wt and 68.5 % wt, respectively. At 28 d, Ag release was 4 ppm from SN and 26.9 ppm from SSN substrates. Colonisation of discs by Staphylococcus aureus was the highest on GB [944 (± 91) × 10 4 CFU/mL], distinctly lower on experimental SN discs [414 (± 117) × 104 CFU/mL] and the lowest on SSN discs [307 (± 126) × 10 4 CFU/mL]. Primary human osteoblasts were abundant 28 d after seeding on GB discs but their adhesion and differentiation, measured by alkaline-phosphatase production, was suppressed by 73 % on SN and by 96 % on SSN discs, in comparison to GB discs. Thus, the PVD-applied Ag coatings differed considerably in their antibacterial effects and osteoconductivity. The experimental SN coating had similar antibacterial effects to the commercially available SSN coating while providing slightly improved osteoconductivity. Balancing the Ag content of Ti implants will be vital for future developments of implants designed for cementless fixation into bone.

Neural crest stem cells protect spinal cord neurons from excitotoxic damage and inhibit glial activation by secretion of brain-derived neurotrophic factor.

The acute phase of spinal cord injury is characterized by excitotoxic and inflammatory events that mediate extensive neuronal loss in the gray matter. Neural crest stem cells (NCSCs) can exert neuroprotective and anti-inflammatory effects that may be mediated by soluble factors. We therefore hypothesize that transplantation of NCSCs to acutely injured spinal cord slice cultures (SCSCs) can prevent neuronal loss after excitotoxic injury. NCSCs were applied onto SCSCs previously subjected to N-methyl-D-aspartate (NMDA)-induced injury. Immunohistochemistry and TUNEL staining were used to quantitatively study cell populations and apoptosis. Concentrations of neurotrophic factors were measured by ELISA. Migration and differentiation properties of NCSCs on SCSCs, laminin, or hyaluronic acid hydrogel were separately studied. NCSCs counteracted the loss of NeuN-positive neurons that was otherwise observed after NMDA-induced excitotoxicity, partly by inhibiting neuronal apoptosis. They also reduced activation of both microglial cells and astrocytes. The concentration of brain-derived neurotrophic factor (BDNF) was increased in supernatants from SCSCs cultured with NCSCs compared to SCSCs alone and BDNF alone mimicked the effects of NCSC application on SCSCs. NCSCs migrated superficially across the surface of SCSCs and showed no signs of neuronal or glial differentiation but preserved their expression of SOX2 and Krox20. In conclusion, NCSCs exert neuroprotective, anti-apoptotic and glia-inhibitory effects on excitotoxically injured spinal cord tissue, some of these effects mediated by secretion of BDNF. However, the investigated NCSCs seem not to undergo neuronal or glial differentiation in the short term since markers indicative of an undifferentiated state were expressed during the entire observation period.

Does hydroxyapatite coating of uncemented cups improve long-term survival? An analysis of 28,605 primary total hip arthroplasty procedures from the Nordic Arthroplasty Register Association (NARA).

OBJECTIVE: It is unclear whether hydroxyapatite (HA) coating of uncemented cups used in primary total hip arthroplasty (THA) improves bone ingrowth and reduces the risk of aseptic loosening. We therefore investigated survival of different uncemented cups that were available with or without HA coating. METHOD: We investigated three different cup types used with or without HA coating registered in the Nordic Arthroplasty Register Association (NARA) database that were inserted due to osteoarthritis (n = 28,605). Cumulative survival rates and adjusted hazard ratios (HRs) for the risk of revision were calculated. RESULTS: Unadjusted 13-year survival for cup revision due to aseptic loosening was 97.9% (CI: 96.5-99.4) for uncoated and 97.8% (CI: 96.3-99.4) for HA-coated cups. Adjusted HRs were 0.66 (CI 0.42-1.04) for the presence of HA coating during the first 10 years and 0.87 (CI 0.14-5.38) from year 10-13, compared with uncoated cups. When considering the endpoint cup revision for any reason, unadjusted 13-year survival was similar for uncoated (92.5% [CI: 90.1-94.9]) and HA-coated (94.7% [CI: 93.2-96.3]) cups. The risk of revision of any component due to infection was higher in THA with HA-coated cups than in THA with uncoated cups (adjusted HR 1.4 [CI 1.1-1.9]). CONCLUSIONS: HA-coated cups have a similar risk of aseptic loosening as uncoated cups, thus the use of HA coating seems to not confer any added value in terms of implant stability. The risk of infection seemed higher in THA with use of HA-coated cups, an observation that must be investigated further.

Interleukin-1 receptor antagonist promotes survival of ventral horn neurons and suppresses microglial activation in mouse spinal cord slice cultures.

Secondary damage after spinal cord injury (SCI) induces neuronal demise through neurotoxicity and inflammation, and interleukin (IL)-1ß is a key inflammatory mediator. We hypothesized that IL-1ß is released in spinal cord slice cultures (SCSC) and aimed at preventing the potentially neurotoxic effects of IL-1ß by using interleukin-1 receptor antagonist (IL1RA). We hypothesized that IL1RA treatment enhances neuronal survival and suppresses microglial activation. SCSC were cultured up to 8 days in vitro (DIV) in the presence of IL1RA or without, either combined with trophic support using neurotrophin (NT)-3 or not. Four groups were studied: negative control, IL1RA, NT-3, and IL1RA + NT-3. IL-1ß concentrations in supernatants were measured by ELISA. SCSC were immunohistochemically stained for NeuN and α-neurofilament, and microglial cells were visualized with isolectin B4 . After 8 DIV, ventral horn neurons were significantly more numerous in the IL1RA, NT-3, and IL1RA + NT-3 groups compared with negative controls. Activated microglial cells were significantly less numerous in the IL1RA, NT-3, and IL1RA + NT-3 groups compared with negative controls. Axons expanded into the collagen matrix after treatment with IL1RA, NT-3, or IL1RA + NT-3, but not in negative controls. IL-1ß release from cultures peaked after 6 hr and was lowest in the IL1RA + NT-3 group. We conclude that IL-1ß is released in traumatized spinal cord tissue and that IL1RA could exert its neuroprotective actions by blocking IL-1-receptors. IL1RA thereby sustains neuronal survival irrespective of the presence of additional trophic support. Microglial activation is suppressed in the presence of IL1RA, suggesting decreased inflammatory activity. IL1RA treatment approaches may have substantial impact following SCI.

Inhibition of microglial and astrocytic inflammatory responses by the immunosuppressant mycophenolate mofetil.

AIMS: Nucleotide depletion induced by the immunosuppressant mycophenolate mofetil (MMF) has been shown to exert neuroprotective effects. It remains unclear whether nucleotide depletion directly counteracts neuronal demise or whether it inhibits microglial or astrocytic activation, thereby resulting in indirect neuroprotection. METHODS: Effects of MMF on isolated microglial cells, astrocyte/microglial cell co-cultures and isolated hippocampal neurones were analysed by immunocytochemistry, quantitative morphometry, and elisa. RESULTS: We found that: (i) MMF suppressed lipopolysaccharide-induced microglial secretion of interleukin-1ß, tumour necrosis factor-α and nitric oxide; (ii) MMF suppressed lipopolysaccharide-induced astrocytic production of tumour necrosis factor-α but not of nitric oxide; (iii) MMF strongly inhibited proliferation of both microglial cells and astrocytes; (iv) MMF did not protect isolated hippocampal neurones from excitotoxic injury; and (v) effects of MMF on glial cells were reversed after treatment with guanosine. CONCLUSIONS: Nucleotide depletion induced by MMF inhibits microglial and astrocytic activation. Microglial and astrocytic proliferation is suppressed by MMF-induced inhibition of the salvage pathway enzyme inosine monophosphate dehydrogenase. The previously observed neuroprotection after MMF treatment seems to be indirectly mediated, making this compound an interesting immunosuppressant in the treatment of acute central nervous system lesions.

A rapid and accurate method to quantify neurite outgrowth from cell and tissue cultures: Two image analytic approaches using adaptive thresholds or machine learning.

BACKGROUND: Assessments of axonal outgrowth and dendritic development are essential readouts in many in vitro models in the field of neuroscience. Available analysis software is based on the assessment of fixed immunolabelled tissue samples, making it impossible to follow the dynamic development of neurite outgrowth. Thus, automated algorithms that efficiently analyse brightfield images, such as those obtained during time-lapse microscopy, are needed. NEW METHOD: We developed and validated algorithms to quantitatively assess neurite outgrowth from living and unstained spinal cord slice cultures (SCSCs) and dorsal root ganglion cultures (DRGCs) based on an adaptive thresholding approach called NeuriteSegmantation. We used a machine learning approach to evaluate dendritic development from dissociate neuron cultures. RESULTS: NeuriteSegmentation successfully recognized axons in brightfield images of SCSCs and DRGCs. The temporal pattern of axonal growth was successfully assessed. In dissociate neuron cultures the total number of cells and their outgrowth of dendrites were successfully assessed using machine learning. COMPARISON WITH EXISTING METHODS: The methods were positively correlated and were more time-saving than manual counts, having performing times varying from 0.5-2 min. In addition, NeuriteSegmentation was compared to NeuriteJ®, that uses global thresholding, being more reliable in recognizing axons in areas of intense background. CONCLUSION: The developed image analysis methods were more time-saving and user-independent than established approaches. Moreover, by using adaptive thresholding, we could assess images with large variations in background intensity. These tools may prove valuable in the quantitative analysis of axonal and dendritic outgrowth from numerous in vitro models used in neuroscience.

Acute total hip arthroplasty combined with internal fixation for displaced acetabular fractures in the elderly: a short-term comparison with internal fixation alone after a minimum of two years.

AIMS: Displaced, comminuted acetabular fractures in the elderly are increasingly common, but there is no consensus on whether they should be treated non-surgically, surgically with open reduction and internal fixation (ORIF), or with acute total hip arthroplasty (THA). A combination of ORIF and acute THA, an approach called 'combined hip procedure' (CHP), has been advocated and our aim was to compare the outcome after CHP or ORIF alone. PATIENTS AND METHODS: A total of 27 patients with similar acetabular fractures (severe acetabular impaction with or without concomitant femoral head injury) with a mean age of 72.2 years (50 to 89) were prospectively followed for a minimum of two years. In all, 14 were treated with ORIF alone and 13 were treated with a CHP. Hip joint and patient survival were estimated. Operating times, blood loss, radiological outcomes, and patient-reported outcomes were assessed. RESULTS: No patient in the CHP group required further hip surgery, giving THA a survival rate of 100% (95% confidence interval (CI) 100 to 100) after three years, compared with 28.6% hip joint survival in the ORIF group (95% CI 12.5 to 65.4; p = 0.001). No dislocations or deep infections occurred in the CHP group. No patient died within the first year after index surgery, but patient survival was lower in the CHP group after three years. There were no relevant differences in patient-reported outcomes. CONCLUSION: The CHP confers a considerably reduced need of further surgery when compared with ORIF alone in elderly patients with complex acetabular fractures. These findings encourage both further use of, and larger prospective studies on, the CHP. Cite this article: Bone Joint J 2019;101-B:478-483.

Risk of early mortality after cemented compared with cementless total hip arthroplasty: a nationwide matched cohort study.

AIMS: It has been suggested that cemented fixation of total hip arthroplasty (THA) is associated with an increased peri-operative mortality compared with cementless THA. Our aim was to investigate this through a nationwide matched cohort study adjusting for age, comorbidity, and socioeconomic background. PATIENTS AND METHODS: A total of 178 784 patients with osteoarthritis who underwent either cemented or cementless THA from the Swedish Hip Arthroplasty Register were matched with 862 294 controls from the general population. Information about the causes of death, comorbidities, and socioeconomic background was obtained. Mortality within the first 90 days after the operation was the primary outcome measure. RESULTS: Patients who underwent cemented THA had an increased risk of death during the first 14 days compared with the controls (hazard ratio (HR) 1.3, confidence interval (CI) 1.11 to 1.44), corresponding to an absolute increase in risk of five deaths per 10 000 observations. No such early increase of risk was seen in those who underwent cementless THA. Between days 15 and 29 the risk of mortality was decreased for those with cemented THA (HR 0.7, CI 0.62 to 0.87). Between days 30 and 90 all patients undergoing THA, irrespective of the mode of fixation, had a lower risk of death than controls. Patients selected for cementless fixation were younger, healthier and had a higher level of education and income than those selected for cemented THA. A supplementary analysis of 16 556 hybrid THAs indicated that cementation of the femoral component was associated with a slight increase in mortality up to 15 days, whereas no such increase in mortality was seen in those with a cemented acetabular component combined with a cementless femoral component. CONCLUSION: This nationwide matched cohort study indicates that patients receiving cemented THA have a minimally increased relative risk of early mortality that is reversed from day 15 and thereafter. The absolute increase in risk is very small. Our findings lend support to the idea that cementation of the femoral component is more dangerous than cementation of the acetabular component. Cite this article: Bone Joint J 2017;99-B:37-43.

Morphological features of the entorhinal-hippocampal connection.

The goal of this review in an overview of the structural elements of the entorhinal-hippocampal connection. The development of the dendrites of hippocampal neurons will be outlined in relation to afferent pathway specificity and the mature dendritic structure compared. Interneurons will be contrasted to pyramidal cells in terms of processing of physiological signals and convergence and divergence in control of hippocampal circuits. Mechanisms of axonal guidance and target recognition, target structures, the involvement of receptor distribution on hippocampal dendrites and the involvement of non-neuronal cellular elements in the establishment of specific connections will be presented. Mechanisms relevant for the maintenance of shape and morphological specializations of hippocampal dendrites will be reviewed. One of the significant contexts in which to view these structural elements is the degree of plasticity in which they participate, during development and origination of dendrites, mature synaptic plasticity and after lesions, when the cells must continue to maintain and reconstitute function, to remain part of the circuitry in the hippocampus. This review will be presented in four main sections: (1) interneurons-development, role in synchronizing influence and hippocampal network functioning; (2) principal cells in CA1, CA3 and dentate gyrus regions-their development, function in terms of synaptic integration, differentiating structure and alterations with lesions; (3) glia and glia/neuronal interactions-response to lesions and developmental guidance mechanisms; and (4) network and circuit aspects of hippocampal morphology and functioning. Finally, the interwoven role of these various elements participating in hippocampal network function will be discussed.

Cell adhesion molecules in neural plasticity and pathology: similar mechanisms, distinct organizations?

Brain plasticity and the mechanisms controlling plasticity are central to learning and memory as well as the recovery of function after brain injury. While it is clear that neurotrophic factors are one of the molecular classes that continue to regulate brain plasticity in the adult central nervous system (CNS), less appreciated but equally profound is the role of cell adhesion molecules (CAMs) in plasticity mechanisms such as long term potentiation, preservation of neurons and regeneration. Ironically, however, CAMs can also reorganize the extra-cellular space and cause disturbances that drive the development of brain pathology in conditions such as Alzheimer's disease and multiple sclerosis. Candidate molecules include the amyloid precursor protein which shares many properties of a classical CAM and beta-amyloid which can masquerade as a pseudo CAM. Beta-Amyloid serves as a nidus for the formation of senile plaques in Alzheimer's disease and like CAMs provides an environment for organizing neurotrophic factors and other CAMs. Inflammatory responses evolve in this environment and can initiate a vicious cycle of perpetuated neuronal damage that is medicated by microglia, complement and other factors. Certain CAMs may converge on common signal transduction pathways involving focal adhesion kinases. Thus a breakdown in the organization of key CAMs and activation of their signal transduction mechanisms may serve as a new principle for the generation of brain pathology.

Triple osteotomy of the pelvis for acetabular dysplasia: age at operation and the incidence of nonunions and other complications influence outcome.

We investigated the variables which determine the outcome after triple osteotomy of the pelvis for the treatment of congenital dysplasia of the hip. We reviewed 51 patients (61 hips) with a median age at operation of 23 years who were treated with a Tönnis triple osteotomy. The median follow-up was six years with a minimum of two years. Eight patients (eight hips) required a revision procedure. Of the remaining 53 hips, the results were good or excellent in 36 (68%) when evaluated according to the Harris hip score (median 90 points), and 33 patients (65%) were satisfied with the procedure. Logistic regression analysis indicated that the incidence of complications such as nonunion at an osteotomy site influenced patient satisfaction (p = 0.079). The incidence of complications correlated positively with increasing patient age at operation (p = 0.004). The amount of acetabular correction did not correlate with patient satisfaction. In univariate analysis, the groups of 'satisfied' and 'not satisfied' patients differed significantly in Harris hip score, age, incidence of nonunion at the osteotomy sites, complications and late revisions. In conclusion, the patient's age at operation and the incidence of complications influence patient satisfaction after triple osteotomy, but the amount of radiologically evident acetabular correction shows no correlation to outcome.

Astrocytic factors deactivate antigen presenting cells that invade the central nervous system.

We hypothesized that CNS tissue has the potential to deactivate invading monocytes/macrophages in order to maintain the immune privilege of the brain, and furthermore, that astrocytes are the cells that initiate monocyte/macrophage deactivation. To test this hypothesis, fluorescent prelabeled rat spleen macrophages with typical amoeboid morphology were transferred into organotypic hippocampal slice cultures (OHSCs), where they gradually developed a ramified morphology similar to the appearance of resting microglial cells. This morphological transformation also occurred if macrophages or monocytes were co-cultured with mixed glial cultures or with astrocytoma cells, and ramification was accompanied by reduced expression of adhesion molecules leukocyte function antigen (LFA)-1, intercellular adhesion molecule (ICAM)-1, and major histocompatibility complex (MHC)-class-II molecules. Moreover, treatment of macrophages with astrocyte culture supernatant effectively down-regulated the LPS-induced expression of adhesion- and MHC-class-II-molecules. Astrocyte supernatant-induced inhibition of adhesion and MHC-class-II-molecule expression was mimicked by transforming growth factor (TGF)-beta1, furthermore, this inhibitory effect was diminished by simultaneous treatment with neutralizing anti-TGF-beta-antibodies. In conclusion, our results suggest that astrocyte-derived, soluble factors that are present in the CNS microenvironment deactivate invading macrophages, thus contributing to the maintenance of CNS immune-privilege following impairment of blood-brain-barrier (BBB) integrity.

Prostaglandin E2 induces expression of P-selectin (CD62P) on cultured human umbilical vein endothelial cells and enhances endothelial binding of CD4-T-cells.

Interaction of endothelial P-selectin with sialyl Lewis(x)-glycoprotein or P-selectin glycoprotein ligand (PSGL)-1 on leukocytes represents an early step in leukocyte recruitment. Redistribution of P-selectin to the endothelial cell surface occurs rapidly after challenge with several proinflammatory agents, for example, histamine, leucopterins, or lipopolysaccharide. We present evidence that prostaglandin E2 (PGE2) is an efficient inductor of surface P-selectin on cultured human umbilical vein endothelial cells (HUVEC). The increase in P-selectin-immunoreactivity coincided with redistribution of cytoplasmic P-selectin-reactive granulae to the endothelial cell surface, as visualized by confocal laser microscopic examination. CD4-T-cell adhesion to PGE2-stimulated HUVEC was also enhanced by a factor of 4, and blocking mAb directed against the binding site of P-selectin almost completely abrogated this increase in CD4-T-cell adhesion. In summary, our findings show that liberation of PGE2 is an important inductor of P-selectin surface expression on endothelial cells, resulting in enhanced recruitment of inflammatory cells.

In vitro analysis of verapamil-induced immunosuppression: potent inhibition of T cell motility and lymphocytic transmigration through allogeneic endothelial cells.

BACKGROUND: Cyclosporine A (CsA) and tacrolimus prevent proliferation but not transendothelial migration of alloreactive lymphocytes into donor organs. As a result, serious adverse effects, such as nephrotoxicity and neurotoxicity, have been observed under CsA/tacrolimus therapy. The incorporation of new drugs with infiltration blocking properties might enhance the efficacy of the current immunosuppressive protocol, allowing lower CsA/tacrolimus dosage. Because Ca2+ plays a critical role in cell-cell interaction, the Ca2+-channel blocker verapamil might be a good cany. didate for supporting CsA/tacrolimus-based therapy. METHODS: A T-cell endothelial cell coculture model or immobilized immunoglobulin G globulin chimeras were employed to investigate how S- and R- verapamil interfere with the lymphocytic infiltration process. The expression and arrangement of membranous adhesion receptors and cytoskeletal F-actin filaments were analyzed by fluorometric method in the presence of. verapamil. RESULTS: Both verapamil enantiomers strongly inhibited lymphocyte infiltration. CD4+ and CD8+ T-cells were influenced to a similar extent with regard to horizontal locomotion (CD4+=CD8+), but to a different extent with regard to adhesion and penetration (CD4+ > CD8+). Moreover, penetration was blocked to a higher extent than was adhesion. ID50-values were 31 microM (CD4+-adhesion) and 11 microM (CD4+-penetration). Verapamil reduced P-selectin expression on endothelial cells and effectively down-regulated binding of T-cells to immobilized P-selectin immunoglobulin G globulins (ID50=4.4 microM; CD4+). A verapamil-induced reduction of intracellular F-actin in T-lymphocytes was proven to be mainly responsible for diminished cell locomotion. CONCLUSIONS: The prevention of CD4+ T-cell penetration by verapamil might argue for its use as an adjunct to CsA/tacrolimus-based immunosuppressive therapy.

Modulation of adhesion molecule expression on endothelial cells by verapamil and other Ca++ channel blockers.

Cytokine-induced expression of adhesion molecules on leukocytes and endothelial cells (EC) is a crucial point in the process of organ transplant rejection. It has been shown that protein kinase C (PKC) is involved in this activation process. Verapamil and other calcium channel blockers seem to possess immunosuppressive qualities in vivo and in vitro; some authors suggested that this is due to PKC- or calmodulin-antagonism. Thus our objectives were to further investigate the second-messenger systems involved in the stimulation of EC and to analyze whether the beneficial influence of calcium channel blockers on the outcome of transplantation is due to impaired expression of adhesion molecules on EC. Our results, obtained in an in vitro model using human umbilical vein EC, show that IL-1-induced expression of intercellular adhesion molecule-1 (ICAM-1) is in part mediated by PKC and that parallel activation of calmodulin is required. Expression of ICAM-1 was reduced to 38.5% by PKC-inhibitor H7 and to 77.2% by calmodulin-inhibitor W7. In addition, data on the intracellular events in TNF-alpha-induced expression of vascular cell adhesion molecule-1 (VCAM-1) is presented, showing that both PKC and, to a higher extent, calmodulin, are involved in this process. Expression of VCAM-1 was reduced to 63.7% by H7 and to 27.7% by W7. IL-1-induced expression of endothelial leukocyte adhesion molecule-1 (ELAM-1) is PKC-dependent but insensitive to blocking of calmodulin. Though activation of adhesion molecule expression utilizes PKC and/or calmodulin as second-messenger pathways the investigated calcium channel blockers verapamil (R- and S-enantiomers), diltiazem and Ro 40-5967 failed to inhibit adhesion molecule expression. Surprisingly, higher concentrations of verapamil (> 12.5 micrograms/ml) or Ro 40-5967 (5 micrograms/ml) significantly enhanced IL-1-induced expression of ELAM-1. ICAM-1-expression was also enhanced by verapamil, but not by Ro 40-5967 or diltiazem. This enhancement was only seen if verapamil was added maximally one hour after the cytokine stimulus indicating that transcriptional modulation is responsible for the observed effects. Our findings indicate that calcium channel blockers have an immunomodulating effect independent of adhesion molecule expression.

Astrocytic factors down-regulate the expression of major histocompatibility complex-class-II and intercellular adhesion molecule-1 on human monocytes.

Several factors contribute to the maintenance of central nervous system immune privilege and astrocytes have been identified as a major source of immunomodulatory cytokines. To investigate whether hematogenous monocytes are immunologically deactivated by astrocyte-derived factors human monocytes were stimulated with lipopolysaccharide or interferon (IFN)-gamma and treated with the supernatant from pure astrocyte cultures, interleukin (IL)-4, IL-10, or with IL-1-receptor antagonist (1L-1-RA). Flow cytometry demonstrated that the supernatant from astrocyte cultures was the most potent agent in reducing the levels of major histocompatibility complex (MHC)-class-II- as well as intercellular adhesion molecule-1-expression, whereas IL-4, IL-10, and IL-1-RA had only marginal effects. The expression of leukocyte function antigen-1 and very late antigen-4 was not modulated by either factor. In conclusion, astrocytes seem to provide soluble factors that have the capacity to deactivate hematogenous monocytes.

[Nora's lesion at the second metacarpal bone of a twelve-year-old female]. / Der interessante Fall: Nora-Läsion am Os metacarpale II eines zwölfjährigen Mädchens.

The extremely rare condition of bizarre parosteal osteochondromatous proliferation (BPOP) was first described in 1983 by the pathologist Nora, and a few more than 100 cases have since been reported. The lesion is defined as a reactive heterotopic ossification and is mostly found in the hands or feet of adults in the third decade of life, although it has also been described in long bones and in other age groups. A high rate of local recurrence of up to 50 % has been noted, but the lesion is benign and does not metastasise. An association with chromosomal rearrangements has recently been described. We here report the case of a 12-year-old girl with a BPOP at the second metacarpal bone, thus at an unusual age. The lesion was marginally resected after biopsy, but recurred locally within 2 years, resulting in subtotal resection of the second metacarpal bone, autologous fibula grafting and temporary external fixation. The clinical, plain radiographic and MRI appearance of the lesion and the prominent histological findings are described, and the difficulties in establishing the correct diagnosis in cases of BPOP are discussed.

[Functional results following Girdlestone arthroplasty]. / Funktionelle Ergebnisse sekundärer Girdlestone-Hüften.

AIM: Aim of the investigation was to identify prognostic factors predicting the level of postoperative function following Girdlestone ("G")-arthroplasty. METHODS: Data were derived from 87 patients, 90 hips, treated with "G"-arthroplasty at one institution between 1983 and 2000. RESULTS: Hip scores amounted to 38.7 (HHS) and 3.5 (Merle) points. The number of previously implanted total hip arthroplasties (THR) did not correlate with the functional result of "G"-arthroplasty (r = - 0.1400; p = 0.4524). On average, the duration of THR prior to "G"-arthroplasty was 44.6 months. Survival time of the latest THR and function of "G"-arthroplasty did not correlate (r = 0.0705; p = 0.7065). Patient age at primary THR, at follow-up, or at "G"-procedure did not correlate with HHS (r = - 0.0367, p = 0.8418, r = 0.1527, p = 0.4121; r = - 0.0151; p = 0.9356, respectively). Time following "G"-arthroplasty, averaging 90.6 months, did not correlate with patients function (r = 0.0920, p = 0.6289). Revision following "G"-procedure and the presence of diabetes positively correlated (p = 0.0104). The appearance of cement in the femoral canal and radiographic signs of persistent bone infection correlated significantly (p = 0.0572). CONCLUSION: Patient age, duration of "G"-hips, and number of prior THR were not reliable to predict the function of "G"-arthroplasty.

[Reimplantation of the artificial hip joint in girdlestone hips is superior to girdlestone arthroplasty by itself]. / Die Reimplantation des künstlichen Gelenkersatzes in Girdlestone Hüften ist der belassenen Girdlestone Situation überlegen.

AIM: The aim of this work was to compare the functional results of secondary Girdlestone hips with the results of total hip replacement (THR) after a Girdlestone situation. METHODS: 72 patients with THR following a Girdlestone situation and 87 patients with a Girdlestone situation (90 hips) were compared with regard to defined endpoints. RESULTS: THR following a Girdlestone situation provided for significantly higher patient satisfaction (89 % versus 13 %) and hip function (HHS 63 versus 39 points). The groups only marginally differed with regard to the incidence of complications (0.32 versus 0.26 per patient) and the necessity for surgical revision (0.38 versus 0.31 per patient). CONCLUSION: Conversion of Girdlestone hips with THR provided patient satisfaction and functional results superior to secondary Girdlestone hips while the incidence of postoperative complications and revisions were similar for both groups. These differences justify attempts at the conversion of Girdlestone situations with THR, if technically possible, in accordance with the patient's wish and as allowed by his/her general health.