[Periprosthetic fractures of the acetabulum: osteosynthesis]. / Periprothetische Frakturen des Acetabulums: Osteosynthese.

In most cases periprosthetic fractures of the acetabulum are complex injuries and are extremely challenging for the treating medical team. Over the years the frequency of this overall rare entity has increased due to demographic changes. In recent years several treatment algorithms were published and provided the possibility of developing standardized treatment concepts. The classification of the fractures and a dedicated preoperative strategy are highly important for the quality of patient-centered care. In the literature the frequency of intraoperative fractures was initially given as 0.4%; however, several studies have been published in which a far higher rate of intraoperative fractures was detected by computed tomography (CT), often referred to as so-called occult fractures. The causes are multifactorial and there is significant association with whether cement-free press-fit acetabular cups were used or cemented forms. In approximately 75% of the cases a low energy impact was the cause of the fracture. In these patients systemic processes, such as osteoporotic alterations of the bony substance or the possible presence of low-grade infections should be considered. This article gives an overview of the diagnostics, planning, challenges and osteosynthetic treatment options for periprosthetic fractures of the acetabulum.

The functional heterogeneity of eosinophil cationic protein is determined by a gene polymorphism and post-translational modifications.

BACKGROUND: The eosinophil is a cytotoxic cell and takes part in parasite killing and tissue-destructive processes by secretion of proteins such as eosinophil cationic protein (ECP). A polymorphism was demonstrated in the ECP gene, giving rise to a substitution of arginine at position 97 with threonine. This polymorphism is related to disease development. OBJECTIVE: To investigate the functional and molecular heterogeneity of native ECP and the functional consequences of the replacement of arginine with a threonine. METHODS: ECP was purified from healthy blood donors by gel filtration, ion-exchange chromatography and reversed-phase chromatography. Recombinant ECPs i.e. rECP 97(arg) and rECP 97(thr) were produced by the pFASTBAC baculovirus expression system. The cytotoxic activity was determined against an erythroleukaemia or a small cell lung cancer cell line. RESULTS: Native ECP was purified to apparent homogeneity and showed a considerable molecular heterogeneity and a corresponding functional heterogeneity with respect to cytotoxic activity. After reduction, the native cytotoxic ECP showed three bands on sodium dodecylsulphate polyacrylamide gel electrophoresis : one major band at 18-20 kDa and two minor bands at about 10 and 5 kDa, respectively. The 5 kDa contained two masses differing with 56.2 Da, which corresponds to the difference in molecular masses of arginine and threonine. rECP 97(arg) was cytotoxic in contrast to rECP97(thr). Deglycosylation with N-glycosidase F did not affect the cytotoxic activity of native ECP to any measurable extent nor the activity of rECP 97(arg), whereas rECP 97(thr) achieved cytotoxic activity. The RNase activities of the recombinant and native ECPs were similar. CONCLUSION: We conclude that ECP is present in several molecular forms with varying biological activities. Some of this functional heterogeneity is based on the genetic polymorphism of the ECP gene and some on post-translational modifications. In subjects carrying the ECP 97(thr) variant, the cytotoxic activity may be disguised by N-linked glycosylation of the active site.

The effect of eosinophils on collagen gel contraction and implications for tissue remodelling.

Asthma is characterized by an eosinophilic inflammation and a subepithelial fibrosis in the airways. Eosinophils contain several cytotoxic substances, such as eosinophil cationic protein (ECP), which can promote inflammation and cause tissue damage. This has generated the hypothesis that eosinophils may drive remodelling of extracellular matrix (ECM). To investigate the role of eosinophils we used an in vitro model for remodelling, the three-dimensional collagen gel contraction assay. Two sources of eosinophils were used in this study, isolated human peripheral eosinophils (purity > 95%) and stimulated [interleukin (IL)-5, IL-3 and granulocyte macrophage-colony stimulating factor (GM-CSF)] HL-60 clone 15 cells. Human eosinophils or HL-60 cells were cast together with human lung fibroblasts (HFL1) in type I collagen gels. Both types of eosinophils augmented fibroblast-mediated collagen gel contraction in a time and concentration-dependent manner. At 48 h, the gel area in HFL1/eosinophil co-culture was 46.5% +/- 0.5 (mean +/- s.e.m.) of initial area and in HFL1 culture 52.3% +/- 0.1 (P < 0.001). Respective figures for HFL1/stimulated HL-60 co-culture and HFL1 culture only were 44.1% +/- 0.5 and 52.4% +/- 0.4 (P < 0.001). The release of ECP was increased when fibroblasts were cultured with eosinophils compared to eosinophils cultured alone. In addition, native ECP added to fibroblast gel cultures also augmented contraction. Our results suggest that eosinophils may interact with mesenchymal cells, promoting remodelling of ECM and that ECP constitutes one potential eosinophil-derived mediator driving this process. We conclude that this may be one important mechanism by which eosinophil-ECM interactions will lead to airway tissue remodelling in asthma.

Monocytes, but not macrophages, produce the eosinophil cationic protein.

The eosinophil cationic protein (ECP) is a cytotoxic protein with ribonuclease activity, produced and stored in bone marrow eosinophil myelocytes. Mature circulating eosinophils contain about 10 pg ECP per cell. The aim of this study was to investigate the possibility that monocytes produce and store ECP. By results from flow cytometry and specific protein measurement it is shown that human monocytes contain ECP (monocytes about 10 fg ECP per cell). RT-PCR analysis indicated the presence of mRNA coding for ECP in blood monocytes but not in alveolar macrophages. Furthermore, mRNA coding for ECP and low amounts of the protein were found in three myeloid cell lines representing different stages of monocytic differentiation. Differentiation of U-937 cells to macrophages induced lowered transcription of the ECP gene and reduced protein production. Immunohistochemical staining of lung tissue indicated that lung macrophages do not contain ECP. It is concluded that ECP is produced to a low extent by human monocytes and that the production is shut down during macrophage differentiation. This might indicate an alternative transcriptional regulation of the ECP gene in the monocytic lineage compared to the eosinophil lineage.

The eosinophil granule proteins in serum, but not the oxidative metabolism of the blood eosinophils, are increased in cancer.

The eosinophil activity in patients with renal cell adenocarcinoma during treatment with interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) was reduced when measured as zymosan-induced lucigenin-enhanced chemiluminescence (CL). Eosinophil cationic protein (ECP), eosinophil peroxidase (EPO) and eosinophil protein-X (EPX) were significantly elevated before and during treatment (P<0.001) when compared with the controls. ECP and EPO were unaffected by the treatment whereas it induced an increased EPX level compared with values measured before treatment (P<0.05). The propensity of eosinophils to secrete their granule proteins may reflect the fact that eosinophils in cancer patients have an enhanced capacity to kill cancer cells.

Monocyte activation in patients with non-seminomatous germ cell tumour of the testis before and after tumour eradication.

AIMS: To investigate the kinetics of normalisation of monocyte oxidative activity following tumour eradication. METHODS: Whole blood lucigenin enhanced chemiluminescence was studied in patients with non-seminomatous germ cell tumours. Group 1 comprised 14 patients who had been "cured" of their cancer (the term "cured" as used in this report denotes a relapse free period of at least three years). Group 2 comprised 15 patients who were followed from diagnosis to up to two years after the start of treatment. RESULTS: Lucigenin enhanced chemiluminescence of whole blood in the "cured" patients was similar to that of controls and lower than that in patients who had not yet received chemotherapy (group 2). After treatment, chemiluminescence decreased slowly and did not normalise until 18 months after the start of treatment. Tumour necrosis factor alpha (TNF alpha) concentrations were normal in "cured" patients but were raised in those who had not yet received treatment. TNF alpha was normalised 12 months after start of treatment. Alpha-fetoprotein concentrations were raised in most patients but normalised rapidly after tumour eradication. CONCLUSIONS: The activity of blood monocytes, as measured by whole blood lucigenin enhanced chemiluminescence, is increased in cancer. This activity may be a consequence of the presence of tumour cells. Immunocompetent cells remain active for over a year after eradication of the tumour.

Patients with renal cancer have a larger proportion of high-density blood monocytes with increased lucigenin-enhanced chemiluminescence.

The production of oxygen metabolites is probably important in cancer cell killing. The production of the superoxide anion, O2-, can be measured by lucigenin-enhanced chemiluminescence (Cl). Previous studies have shown that whole-blood lucigenin-enhanced Cl is increased in cancer patients and that this increase is related to blood monocyte activity. The present investigation confirmed these findings and showed that whole-blood lucigenin-enhanced Cl was elevated in 17 patients with renal cell adenocarcinoma (P < 0.001). The activity of the monocytes was studied more in detail, whereby monocytes were separated into different populations based upon differences in densities, i.e., high-density and low-density monocytes. The cancer patients had a significantly larger proportion of high-density monocytes (P < 0.05) than controls. The lucigenin-enhanced Cl of purified high-density monocytes in controls was significantly higher than that of low-density monocytes (P < 0.01). The authors conclude that the increase in the lucigenin-enhanced Cl of whole blood observed in cancer patients may partly reflect the increased activity of a larger proportion of high-density monocytes in these patients.

Lucigenin-enhanced chemiluminescence in blood is increased in cancer.

The production of oxygen-derived cytotoxic metabolites by phagocytic cells is probably important in cancer cell killing. This production can be measured by chemiluminescence (CL). In the present report the authors have measured luminol and lucigenin-enhanced CL in whole blood from 63 untreated patients with cancer. In particular, the lucigenin-enhanced CL was increased in patients with cancer (P less than 0.001). No relation to origin or spread of the cancer was obvious. Monocyte number in peripheral blood was also significantly (P less than 0.01) increased as compared with age-matched controls. Further, the lucigenin-enhanced CL of purified monocytes, but not that of purified polymorphonuclear leukocyte(s) (PMNs), correlated significantly (P = 0.002) with the activity of whole blood. The authors conclude therefore that the highly increased lucigenin-enhanced CL observed in whole blood of a patient with cancer may reflect the enhanced production and activity of circulating monocytes that is a consequence of the body's defense reactions toward the developing cancer.

Transformation of cucumber (Cucumis sativus L.) plants with Agrobacterium rhizogenes.

Transgenic cucumber plants (Cucumis sativus L., cv. 'Straight Eight') were regenerated from roots induced by inoculation of inverted hypocotyl sections with Agrobacterium rhizogenes containing the vector pARC8 in addition to the resident Ri-plasmid. The DNA transferred to the plant from the vector (T-DNA) included a gene which encoded the enzyme neomycin phosphotransferase II, and thus conferred on the plant cells resistance to kanamycin. The transgenic plants looked normal and were positive for the neomycin phosphotransferase II. Southern blot analysis of the transgenic plants revealed that all plants contained vector DNA, but only some of them contained DNA from the Ri plasmid.