[Intraosseous foreign body or osteoma : Challenging differential diagnosis after open radius fracture]

Vorstellung eines 16-jährigen Patienten nach Fahrradsturz beim Mountainbiken 14 Tage nach primärer Versorgung nach offener Epiphysenverletzung. Metaphysär intraossär liegende Steine wurden bei anatomischer Reposition der Fraktur als nebenbefundliches Osteom fehlinterpretiert.

An O-Glycosylation of Fibronectin Mediates Hepatic Osteodystrophy Through α4β1 Integrin

Patients with cholestatic liver disease experience increased fracture risk. Higher circulating levels of a fibronectin isoform called oncofetal fibronectin (oFN) were detected in a subset of such patients. Administering this isoform to mice suppresses osteoblast differentiation and diminishes bone mineral density in vivo, suggesting it is responsible for bone loss in cholestatic liver disease. The aim of this study was to define the mechanism by which oFN affects osteoblast function and evaluate possible modifiers in experimental hepatic osteodystrophy. The fibronectin isoform oFN is characterized by the presence of various glycosylations. In line with this, adding oFN that underwent enzymatic O-deglycosylation to osteoblasts normalized nodule formation in vitro. Of three possible O-glycosylation sites in oFN, only a mutation at AA 33 of the variable region or binding of this glycosylated site with an antibody normalized osteoblast differentiation. Because the responsible site is located in the variable region of fibronectin, which binds to α4β1 or α4β7 integrins, these integrins were evaluated. We show that integrin α4β1 mediates the inhibitory effect of oFN both in vitro as well as in vivo. In a hepatic osteodystrophy mouse model, we demonstrate that liver fibrosis is associated with increased circulating oFN and diminished BMD. In addition, trabecular bone loss induced by oFN injection or fibrosis induction could be prevented by either administering an antibody that binds to α4 integrin (PS/2) or the CS1 peptide, which contains a binding site for α4β1 integrin. In summary, oFN inhibits osteoblast activity. This is because of an O-glycosylation in the variable region that results in decreased integrin-mediated signaling. This deleterious effect can be thwarted by binding α4β1 integrin. Thus, we have characterized the defect and the receptor mediating bone loss in patients with hepatic osteodystrophy and evaluated possible therapeutic interventions in a murine model. © 2016 American Society for Bone and Mineral Research.

EDA-Fibronectin Originating from Osteoblasts Inhibits the Immune Response against Cancer

Osteoblasts lining the inner surface of bone support hematopoietic stem cell differentiation by virtue of proximity to the bone marrow. The osteoblasts also modify their own differentiation by producing various isoforms of fibronectin (FN). Despite evidence for immune regulation by osteoblasts, there is limited knowledge of how osteoblasts modulate cells of the immune system. Here, we show that extra domain A (EDA)-FN produced by osteoblasts increases arginase production in myeloid-derived cells, and we identify α5β1 as the mediating receptor. In different mouse models of cancer, osteoblasts or EDA-FN was found to up-regulate arginase-1 expression in myeloid-derived cells, resulting in increased cancer growth. This harmful effect can be reduced by interfering with the integrin α5β1 receptor or inhibiting arginase. Conversely, in tissue injury, the expression of arginase-1 is normally beneficial as it dampens the immune response to allow wound healing. We show that EDA-FN protects against excessive fibrotic tissue formation in a liver fibrosis model. Our results establish an immune regulatory function for EDA-FN originating from the osteoblasts and identify new avenues for enhancing the immune reaction against cancer.

Osteoblasts produce an isoform of fibronectin (EDA-fibronectin) that acts on myeloid cells to increase arginase-1 expression and protect against fibrosis. However, it can also enhance cancer growth; interfering with the interaction between EDA-fibronectin and its receptor diminishes this effect.

Osteoblasts, which are the cells that produce bone, line the inner surface of the bone and are adjacent to the marrow that generates all the different blood cells. Osteoblasts have a close relationship with hematopoiesis, and it has been shown that a transient elimination of osteoblasts leads to the decrease of hematopoietic stem cells and progenitor cells. Fibronectin (FN) is an extracellular matrix protein with a known role in hematopoiesis in vitro that is secreted by osteoblasts. Here, we analyze the role of FN in hematopoiesis and find that an isoform that contains the extra domain A (EDA) and is produced by the osteoblasts affects both the number and future behavior of a subset of immune cells. EDA-FN protects against excessive fibrotic tissue formation in a liver fibrosis model. The same process, however, is detrimental in cancer, because it prevents the organism from mounting a potent immune response against the cancer and induces an increase of cancer growth. Mechanistically, we find that the EDA domain binds to the cell surface receptor α5β1 integrin and enhances the production of the anti-inflammatory and immunosuppressive factor arginase-1. We conclude that EDA-FN production by osteoblasts modulates immune cell behavior, and that interfering with this mechanism opens up new possibilities for enhancing an immune reaction against cancer.

Age-Related Changes of 14-3-3 Isoforms in Midbrain of A53T-SNCA Overexpressing Mice

BACKGROUND

Parkinson's disease (PD) is characterized by loss of midbrain dopaminergic neurons, which are affected by cytoplasmic inclusions, named Lewy pathology. The main component is alpha-synuclein (SNCA), a protein modulating SNARE-complex dependent neurotransmission. SNCA mutations trigger dominantly inherited PD variants and sporadic cases of PD via aggregation and transmission. SNCA and isoforms of the 14-3-3 family show sequence homology, protein interaction and joint aggregation, so 14-3-3 s may be key molecules of pathogenesis.

OBJECTIVE

We aimed to identify the relevant isoforms in midbrain and to distinguish for the first time the changes that occur very early versus those that progress with pathology.

METHODS

We assessed expression of the 14-3-3 family with quantitative RT-PCR and immunoblots of differential solubility fractions in mice with A53T-SNCA overexpression longitudinally at different ages.

RESULTS

Transcript levels showed reductions at age 3 months with increases at later ages for the beta, eta and zeta isoforms. Protein levels at age 3 months exhibited a concordant reduction only for beta, while increased insolubility was observed for epsilon and zeta. At age 18 months only the reduction of 14-3-3 beta protein remained significant. Thus, the toxic gain-of-function of alpha-synuclein leads to early transitory alterations of several 14-3-3 isoforms. When the levels of soluble 14-3-3 proteins become apparently normal during later life, increasing amounts of beta, eta and zeta mRNA are produced, possibly to compensate for protein insolubility and aggregation in a SNCA/14-3-3 complex.

CONCLUSIONS

These data may contribute to identify key molecular events that reflect Parkinson's disease risk and progression.

Complexin-1 and Foxp1 Expression Changes Are Novel Brain Effects of Alpha-Synuclein Pathology

As the second most frequent neurodegenerative disorder of the aging population, Parkinson’s disease (PD) is characterized by progressive deficits in spontaneous movement, atrophy of dopaminergic midbrain neurons and aggregation of the protein alpha-synuclein (SNCA). To elucidate molecular events before irreversible cell death, we studied synucleinopathy-induced expression changes in mouse brain and identified 49 midbrain/brainstem-specific transcriptional dysregulations. In particular complexin-1 (Cplx1), Rabl2a and 14-3-3epsilon (Ywhae) downregulation, as well as upregulation of the midbrain-specific factor forkhead box P1 (Foxp1) and of Rabgef1, were interesting as early mRNA level effects of alpha-synuclein triggered pathology. The protein levels of complexin-1 were elevated in midbrain/brainstem tissue of mice with A53T-SNCA overexpression and of mice with SNCA-knockout. The response of CPLX1 and Foxp1 levels to SNCA deficiency supports the notion that these factors are regulated by altered physiological function of alpha-synuclein. Thus, their analysis might be useful in PD stages before the advent of Lewy pathology. Because both alpha-synuclein and complexin-1 modulate vesicle release, our findings support presynaptic dysfunction as an early event in PD pathology.

Efficacy of oxaliplatin plus 5-fluorouracil/leucovorin (FOLFOX4) versus doxorubicin in advanced HCC: Updates on the EACH study

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Background: In Asia, where hepatitis B is very common, patients often present with locally advanced or metastatic hepatocellular carcinoma (HCC), and their prognosis is poor. The EACH study was designed to evaluate the efficacy and safety of FOLFOX4 vs. doxorubicin as palliative systemic chemotherapy in advanced HCC.

Methods: The open-label, randomized, multicenter phase III study was conducted in 371 patients in China, Taiwan, Korea and Thailand, who had locally advanced or metastatic HCC and were ineligible for resection. Patients were randomized 1:1 to receive either FOLFOX4 (oxaliplatin 85 mg/m2 i.v. d1; LV 200 mg/m2 i.v. h0–h2 d1 and d2; 5FU 400 mg/m2 i.v. bolus h2, then 600 mg/m2 over 22 hours d1 and d2 q2w) or doxorubicin (50 mg/m2 i.v. q3w). The primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS), response rate (RR) by RECIST and safety. Data from final and follow-up analyses of the intent-to-treat (ITT) population and selected subgroup analyses are presented.

Results: At the final analysis, median OS with FOLFOX4 (N = 184) was 6.40 months (95% CI: 5.30, 7.03) vs. 4.97 months (95% CI: 4.23, 6.03) with doxorubicin [N = 187; p = 0.0695 using a stratified log-rank test; statistical significance (p = 0.0425) was achieved at the post hoc follow-up analysis conducted 7 months later]. Median PFS with FOLFOX4 was 2.93 months (95% CI: 2.43, 3.53) vs. 1.77 months with doxorubicin (95% CI: 1.63, 2.30; p = 0.0002). The RR was 8.2% vs. 2.7% of patients with FOLFOX4 and doxorubicin, respectively (p = 0.0233), and the disease control rate (DCR) was 52.2% vs. 31.6% (p < 0.0001). In the Chinese sub-population, OS, PFS, RR and DCR were significantly improved with FOLFOX4 vs. doxorubicin at both the final and follow-up analyses. In the other subgroups analyzed, the OS and PFS benefits of FOLFOX4 vs. doxorubicin were generally consistent.

Conclusions: In the ITT population, median OS was greater with FOLFOX4 than doxorubicin throughout the study and statistical significance was achieved after continued follow-up. FOLFOX4 can benefit patients with advanced HCC, as it significantly increases median OS, PFS, RR and DCR compared with doxorubicin.

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Prognosis of the adenocarcinoma of the cervix uteri: a comparative study

The different prognoses for patients with adenocarcinomas and squamous cell carcinomas of the cervix uteri were proved by matched-pair analysis. One hundred forty-four patients with adenocarcinoma treated in 1964-1985 were compared in a ratio of 1:2 with 268 patients with squamous cell carcinoma comparable in age, stage, and treatment modality. In both groups 45% of patients were in stage I, 38% in stage II, 15% in stage III, and 2% in stage IV. Five- and 10-year survivals of patients with adenocarcinoma were significantly lower than for those with squamous cell carcinoma (53% resp. 42% vs 68% vs 58%, P = 0.006). In an analyses of patients' prognosis according to clinical stage there was no significant difference between both groups in stages III and IV treated exclusively by radiotherapy. No significant differences were found in stage I and II patients treated by radical surgery. However, the most significant difference in prognosis was seen in stage I and II patients treated by radiotherapy. Five-year survival was 58.6% in stage I adenocarcinomas compared with 85.0% in squamous cell carcinomas. It can be concluded from these results that a discussion of the problem of FIGO staging is more necessary than a discussion of the different radiosensitivities of these two histological types. Surgical treatment must have the same priority as radical surgery or staging laparotomy for exact histologic staging in adenocarcinomas of the cervix uteri.

Insulin-gene expression in extrafetal membranes of rats

We quantified fetal rat extrapancreatic insulin-gene expression by measuring mRNA in the yolk sac and placenta. Yolk sac makes a significant contribution to the total fetal insulin stores. The placenta contains a much smaller amount of insulin mRNA. Yolk sac insulin mRNA is barely detectable at 16 days gestation but increases markedly to a maximum at 21 days, 1 day before birth. In contrast to the pancreatic 550-nucleotide (n) insulin mRNA, yolk sac has a 720-n mRNA. However, on removal of the terminal poly(A), both transcripts produce a 440-n RNA, the size predicted for a fully processed insulin mRNA.