80 research outputs found

    Effect of sonic hedgehog/β-TCP composites on bone healing within the critical-sized rat femoral defect

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    The creation of entirely synthetically derived bone substitute materials which are as effective as autologous bone grafts is desirable. Osteogenesis involves the concerted action of several proteins within a signaling cascade. Hedgehog proteins act upstream of this cascade, inducing the expression of various bone morphogenetic proteins (BMPs) and promoting physiological bone healing. Therefore, the hypothesis that hedgehog signaling in bone defects improves bone healing more than BMP signaling alone was tested. Recombinant N-terminal sonic hedgehog protein (N-SHh), BMP-2 or a combination of the two was added to β-tricalcium phosphate (β-TCP) and 5-mm femoral midshaft defects in nude rats were filled with these composites. The defects were stabilized with mini-plates. After eight weeks, the animals were sacrificed and the femora were explanted. The radiological evaluation was followed by a three-point bending test and histological examination. BMP-2/β-TCP composites showed a trend of increased stiffness compared with the controls (β-TCP without protein). N-SHh/β-TCP composites had lower stiffness compared with the control group and the N-SHh/BMP-2/β-TCP composites also had lower average stiffness compared with the controls (all not significant). Histomorphometry, however, revealed abundant cartilage and bone core formation in the N-SHh-composite groups. The sum of the new cartilage and bone was highest in the combination group N-SHh/BMP-2 (not significant). The addition of N-SHh to bone substitute materials appears to delay bone healing at the applied concentration and observation time but also showed a trend for higher amounts of ossifying cartilage

    Polyclonal Proliferation of Large Granular Lymphocytes during Cytomegalovirus Primary Infection in a Human Immunodeficiency Virus—Infected Patient Receiving Antiretroviral Therapy

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    We report the first case of a patient infected with HIV in whom polyclonal CD8+/CD57- T lymphocyte large granular lymphocyte (LGL) proliferation was observed in association with cytomegalovirus primary infection. Because the differential diagnosis of an increased number of LGLs includes both monoclonal LGL leukemia and polyclonal proliferation of LGL, patients in whom LGL proliferation is detected always need close hematological and clinical observation to determine whether therapeutic intervention is necessar

    Hyperlipidemic myeloma: review of 53 cases

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    Hyperlipidemic myeloma is a rare and poorly understood variant of multiple myeloma. We report the case of a 53-year-old woman with hyperlipidemic myeloma, skin xanthomas and hyperviscosity syndrome who underwent allogeneic bone marrow transplantation. A comprehensive literature search identified 52 additional cases with plasma cell disease and hyperlipidemia. A detailed analysis revealed several characteristics of these patients as compared to multiple myeloma with normal lipid status: (1) IgA paraprotein was present in the majority (53% vs. 21% in classical multiple myeloma). (2) Skin xanthomas, especially in the palmar creases, elbows, and knees were common (70%). (3) Hyperviscosity syndrome occurred more often (26% vs. 2-6%). While conventional lipid-lowering therapy had only marginal effects, successful anti-myeloma therapy also reduced hyperlipidemia. Analyses of the mechanisms leading to hyperlipidemia documented complexes of paraprotein and lipoprotein in 75% of the 32 cases tested, suggesting an inhibitory role of the paraprotein on lipid degradation. In conclusion, the clinical characteristics, the therapeutic options, and the pathophysiologic mechanisms of hyperlipidemic myeloma are comprehensively reported using the available data from all 53 published cases in the literatur

    Elevated ratio of MMP2/MMP9 activity is associated with poor response to chemotherapy in osteosarcoma

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    Background: Matrix metalloproteinases (MMPs) are crucially involved in the regulation of multiple stages of cancer progression. Elevated MMP levels have been associated with the development of metastases and poor prognosis in several types of cancer. However, the role of MMPs in osteosarcoma and their prognostic value is still unclear. Available data are conflicting, most likely due to different technical approaches. We hypothesized that in contrast to total mRNA or protein levels frequently analyzed in previous studies the enzymatic activities of MMPs and their inhibitors the tissue inhibitors of matrix metalloproteinases (TIMPs) are closer related to their biological functions. We therefore aimed to evaluate the reliability of different zymography techniques for the quantification of MMP and TIMP activities in osteosarcoma biopsies in order to investigate their distribution, possible regulation and prognostic value. Methods: All analyses were done using cryo-conserved osteosarcoma pretreatment biopsies (n = 18). Gene and protein expression of MMPs and TIMPs were analyzed by RT-qPCR and western blot analysis, respectively. Overall MMP activity was analyzed by in situ zymography, individual MMP activities were analyzed by gelatin zymography. Reverse zymography was used to detect and quantify TIMP activities. Results: Strong overall MMP activities could be detected in osteosarcoma pretreatment biopsies with MMP2 and MMP9 as predominant active MMPs. In contrast to total RNA or protein expression MMP2 and MMP9 activities showed significant quantitative differences between good and poor responders. While MMP9 activity was high in the good responder group and significantly decreased in the poor responder group, MMP2 activity showed a reverse distribution. Likewise, significant differences were detected concerning the activity of TIMPs resulting in a negative correlation of TIMP1 activity with MMP2 activity (p = 0.044) and negative correlations of TIMP2 and TIMP3 with MMP9 activity (p = 0.007 and p = 0.006). Conclusion: In contrast to mRNA or protein levels MMP and TIMP activities showed significant differences between the analyzed good and poor responder groups. A shift from MMP9 to predominant MMP2 activity is associated with poor response to chemotherapy suggesting that the ratio of MMP2/MMP9 activity might be a valuable and easily accessible marker to predict the response to chemotherapy in osteosarcoma

    Circular dichroism spectra of β-peptides: sensitivity to molecular structure and effects of motional averaging

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    Circular dichroism spectra of two β-peptides, i.e. peptides composed of β-amino acids, calculated using ensembles of configurations obtained by molecular dynamics simulation are presented. The calculations were based on 200ns simulations of a β-heptapeptide in methanol at 298K and 340K and a 50ns simulation of a β-hexapeptide in methanol at 340K. In the simulations the peptides sampled both folded (helical) and unfolded structures. Trajectory structures with common backbone conformations were identified and grouped into clusters. The CD spectra were calculated for individual structures, based on peptide-group dipole transition moments obtained from semi-empirical molecular orbital theory and using the so-called matrix method. The single-structure spectra were then averaged over entire trajectories and over clusters of structures. Although certain features of the experimental CD spectra of the β-peptides are reproduced by the trajectory-average spectra, there exist clear differences between the two sets of spectra in both wavelength and peak intensities. The analysis of individual contributions to the average spectra shows that, in general, the interpretation of a CD signal in terms of a single structure is not possible. Moreover, there is a large variation in the CD spectra calculated for a set of individual structures that belong to the same cluster, even when a structurally tight clustering criterion is used. This indicates that the CD spectra of these peptides are very sensitive to small local structural difference

    Transvenous Biopsy of Cavo-Atrial Tumors with the Quick-Core Needle

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    A variant application of the renal Quick-Core needle in 3 patients with cavo-atrial tumors is reported. In all 3 patients either a transjugular or transfemoral venous biopsy approach with this device yielded sufficient tissue for histological diagnosis at the first attempt. Bioptic diagnoses were confirmed either by surgery or radiological and clinical response to a specific chemotherapy. There were no procedure-related complication

    Hypoxia and reoxygenation do not upregulate adhesion molecules and natural killer cell adhesion on human endothelial cells in vitro

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    Objectives: Ischemia/reperfusion injury is characterized by endothelial cell activation leading to increased expression of adhesion molecules such as inter-cellular adhesion molecule (ICAM)-1, vascular cell adhesion molecule (VCAM)-1, endothelial- and platelet-selectin (E- and P-selectin), and to the subsequent recruitment of leukocytes. The aim of the present study was to investigate the respective effects of a proinflammatory cytokine (tumor necrosis factor alpha , TNF-α), hypoxia and/or reoxygenation on adhesion molecule expression and natural killer (NK) cell adhesion in an in vitro model of I/R. Methods: Human aortic endothelial cells (HAEC) were stimulated in vitro for 8h with TNF-α (1000 U/ml) and exposed to hypoxia (1% O2), reoxygenation (21% O2) or different combinations thereof. Cell surface expression of ICAM-1, VCAM-1 and E-/P-selectin on HAEC was analyzed by flow cytometry, and culture supernatants were tested for soluble adhesion molecules by ELISA. Rolling adhesion of NK cells on HAEC was determined using a rotating assay. Results: Untreated HAEC constitutively expressed ICAM-1 on their surface but neither expressed E-/P-selectin, VCAM-1, nor shedded soluble adhesion molecules. Exposure of HAEC to hypoxia or hypoxia and reoxygenation did not upregulate cell surface expression or shedding of adhesion molecules. In contrast, TNF-α significantly upregulated cell surface expression of ICAM-1, VCAM-1, and E-/P-selectin and led to the shedding of ICAM-1 and E-selectin. Combined treatment of HAEC with TNF-α, hypoxia and reoxygenation reduced E-/P-selectin surface expression and enhanced E-selectin shedding, but did not further influence ICAM-1 and VCAM-1. Soluble VCAM-1 was not detected. NK cell adhesion on HAEC increased 4-fold after TNF-α stimulation, but was not affected by hypoxia or hypoxia and reoxygenation. Conclusions: Both the expression of endothelial adhesion molecules and rolling NK cell adhesion was upregulated by TNF-α but not by hypoxia alone or hypoxia followed by reoxygenation supporting the view that anti-inflammatory treatment may reduce ischemia/reperfusion injur

    Efficacy of omalizumab in mastocytosis: allusive indication obtained from a prospective, double-blind, multicenter study (XOLMA Study)

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    BACKGROUND: Patients with mastocytosis often suffer from a variety of symptoms caused by mast cell mediators where treatments remain difficult, showing various success rates. Omalizumab, a monoclonal anti-IgE antibody, has been postulated to have a positive impact on mastocytosis-associated symptoms such as flush, vertigo, gastrointestinal problems, or anaphylaxis. OBJECTIVE: To investigate the efficacy and safety of omalizumab in systemic mastocytosis. METHODS: Patients with histologically proven mastocytosis were investigated in a multicenter prospective double-blind placebo-controlled trial to receive either omalizumab or placebo, dosed according to IgE and body weight. The primary endpoint was change in the AFIRMM activity score after 6 months of treatment. Different laboratory parameters were analyzed. RESULTS: Sixteen patients were analyzed: 7 to omalizumab and 9 to placebo (mean age 47.7 ± 13.8 vs. 45.4 ± 8.8 years; 66.6 vs. 85.7% were female; mean disease duration 10.0 ± 5.1 vs. 4.5 ± 2.9 years, respectively). After 6 months the median AFIRMM score decreased 50% from 52.0 to 26.0 in the omalizumab group versus 104.0-102.0 in the placebo group (p = 0.286); however, the difference was not significant (p = 0.941). Secondary endpoints, including the number of allergic reactions, changes in major complaints, wheal-and-flare reaction due to mechanical irritation (Darier's sign), and frequency of the use of mastocytosis-specific drugs improved in the omalizumab group, but not significantly. Adverse events like urticaria, bronchospasm, and anaphylactic shock showed no significant difference between the groups. No severe adverse events occurred. FcεRI (Fc-epsilon receptor) expression on basophils decreased after receiving omalizumab versus placebo. CONCLUSION: Omalizumab was safe and showed a tendency to improve mastocytosis-related symptoms, in particular diarrhea, dizziness, flush, and anaphylactic reactions, including the AFIRMM score and secondary endpoints; however, the difference was not significant. Due to the small study size and difference at baseline between the study groups, further studies are required to confirm our findings
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