The European multicenter trial on the safety and efficacy of guided oblique lumbar interbody fusion (GO-LIF)

Background: Because of the implant-related problems with pedicle screw-based spinal instrumentations, other types of fixation have been tried in spinal arthrodesis. One such technique is the direct trans-pedicular, trans-discal screw fixation, pioneered by Grob for spondylolisthesis. The newly developed GO-LIF procedure expands the scope of the Grob technique in several important ways and adds security by means of robotic-assisted navigation. This is the first clinical trial on the GO-LIF procedure and it will assess safety and efficacy. Methods/Design: Multicentric prospective study with n = 40 patients to undergo single level instrumented spinal arthrodesis of the lumbar or the lumbosacral spine, based on a diagnosis of: painful disc degeneration, painful erosive osteochondrosis, segmental instability, recurrent disc herniation, spinal canal stenosis or foraminal stenosis. The primary target criteria with regards to safety are: The number, severity and cause of intra-and perioperative complications. The number of significant penetrations of the cortical layer of the vertebral body by the implant as recognized on postoperative CT. The primary target parameters with regards to feasibility are: Performance of the procedure according to the preoperative plan. The planned follow-up is 12 months and the following scores will be evaluated as secondary target parameters with regards to clinical improvement: VAS back pain, VAS leg pain, Oswestry Disability Index, short form - 12 health questionnaire and the Swiss spinal stenosis questionnaire for patients with spinal claudication. The secondary parameters with regards to construct stability are visible fusion or lack thereof and signs of implant loosening, implant migration or pseudarthrosis on plain and functional radiographs. Discussion: This trial will for the first time assess the safety and efficacy of guided oblique lumbar interbody fusion. There is no control group, but the results, the outcome and the rate of any complications will be analyzed on the background of the literature on instrumented spinal fusion. Despite its limitations, we expect that this study will serve as the key step in deciding whether a direct comparative trial with another fusion technique is warranted

An agonist sensitive, quick and simple cell-based signaling assay for determination of ligands mimicking prostaglandin E2 or E1 activity through subtype EP1 receptor: Suitable for high throughput screening

<p>Abstract</p> <p>Background</p> <p>Conventionally the active ingredients in herbal extracts are separated into individual components, by fractionation, desalting, and followed by high-performance liquid chromatography (HPLC). In this study we have tried to directly screen water-soluble fractions of herbs with potential active ingredients before purification or extraction. We propose that the herbal extracts mimicking prostaglandin E₁(PGE₁) and E₂(PGE₂) can be identified in the water-soluble non-purified fraction. PGE₁is a potent anti-inflammatory molecule used for treating peripheral vascular diseases while PGE₂is an inflammatory molecule.</p> <p>Methods</p> <p>We used cell-based assays (CytoFluor multi-well plate reader and fluorescence microscopy) in which a calcium signal was generated by the recombinant EP₁receptor stably expressed in HEK293 cells (human embryonic kidney). PGE₁and PGE₂were tested for their ability to generate a calcium signal. Ninety-six water soluble fractions of Treasures of the east (single Chinese herb dietary supplements) were screened.</p> <p>Results</p> <p>After screening, the top ten stimulators were identified. The identified herbs were then desalted and the calcium fluorescent signal reconfirmed using fluorescence microscopy. Among these top ten agonists identified, seven stimulated the calcium signaling (1-40 μM concentration) using fluorescence microscopy.</p> <p>Conclusions</p> <p>Fluorescence microscopy and multi-well plate readers can be used as a target specific method for screening water soluble fractions with active ingredients at a very early stage, before purification. Our future work consists of purifying and separating the active ingredients and repeating fluorescence microscopy. Under ordinary circumstances we would have to purify the compounds first and then test all the extracts from 96 herbs. Conventionally, for screening natural product libraries, the procedure followed is the automated separation of all constituents into individual components using fractionation and high performance liquid chromatography. We, however, demonstrated that the active ingredients of the herbal extracts can be tested before purification using an agonist sensitive, quick and simple cell-based signaling assay for ligands mimicking the agonists, PGE₁and PGE₂.</p

Hypoxia and Prostaglandin E Receptor 4 Signalling Pathways Synergise to Promote Endometrial Adenocarcinoma Cell Proliferation and Tumour Growth

The prostaglandin endoperoxide synthase (PTGS) pathway is a potent driver of tumour development in humans by enhancing the biosynthesis and signalling of prostaglandin (PG) E2. PTGS2 expression and PGE2 biosynthesis is elevated in endometrial adenocarcinoma, however the mechanism whereby PTGS and PGE2 regulate endometrial tumour growth is unknown. Here we investigated (a) the expression profile of the PGE synthase enzymes (PTGES, PTGES-2, PTGES-3) and PGE receptors (PTGER1–4) in endometrial adenocarcinomas compared with normal endometrium and (b) the role of PTGER4 in endometrial tumorigenesis in vivo. We found elevated expression of PTGES2 and PTGER4 and suppression of PTGER1 and PTGER3 in endometrial adenocarcinomas compared with normal endometrium. Using WT Ishikawa endometrial adenocarcinoma cells and Ishikawa cells stably transfected with the full length PTGER4 cDNA (PTGER4 cells) xenografted in the dorsal flanks of nude mice, we show that PTGER4 rapidly and significantly enhances tumour growth rate. Coincident with enhanced PTGER4-mediated tumour growth we found elevated expression of PTGS2 in PTGER4 xenografts compared with WT xenografts. Furthermore we found that the augmented growth rate of the PTGER4 xenografts was not due to enhanced angiogenesis, but regulated by an increased proliferation index and hypoxia. In vitro, we found that PGE2 and hypoxia independently induce expression of PTGER4 indicating two independent pathways regulating prostanoid receptor expression. Finally we have shown that PGE2 and hypoxia synergise to promote cellular proliferation of endometrial adenocarcinoma cells

Proneoplastic effects of PGE2 mediated by EP4 receptor in colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Prostaglandin E₂(PGE₂) is the major product of Cyclooxygenase-2 (COX-2) in colorectal cancer (CRC). We aimed to assess PGE₂cell surface receptors (EP 1–4) to examine the mechanisms by which PGE₂regulates tumour progression.</p> <p>Methods</p> <p>Gene expression studies were performed by quantitative RT-PCR. Cell cycle was analysed by flow cytometry with cell proliferation quantified by BrdU incorporation measured by enzyme immunoassay. Immunohistochemistry was employed for expression studies on formalin fixed paraffin embedded tumour tissue.</p> <p>Results</p> <p>EP4 was the most abundant subtype of PGE₂receptor in HT-29 and HCA7 cells (which show COX-2 dependent PGE₂generation) and was consistently the most abundant transcript in human colorectal tumours (n = 8) by qRT-PCR (ANOVA, p = 0.01). G0/G1 cell cycle arrest was observed in HT-29 cells treated with SC-236 5 μM (selective COX-2 inhibitor) for 24 hours (p = 0.02), an effect abrogated by co-incubation with PGE₂(1 μM). G0/G1 arrest was also seen with a specific EP4 receptor antagonist (EP4A, L-161982) (p = 0.01). Treatment of HT-29 cells with either SC-236 or EP4A caused reduction in intracellular cAMP (ANOVA, p = 0.01). Early induction in p21^WAF1/CIP1expression (by qRT-PCR) was seen with EP4A treatment (mean fold increase 4.4, p = 0.04) while other genes remained unchanged. Similar induction in p21^WAF1/CIP1was also seen with PD153025 (1 μM), an EGFR tyrosine kinase inhibitor, suggesting EGFR transactivation by EP4 as a potential mechanism. Additive inhibition of HCA7 proliferation was observed with the combination of SC-236 and neutralising antibody to amphiregulin (AR), a soluble EGFR ligand. Concordance in COX-2 and AR localisation in human colorectal tumours was noted.</p> <p>Conclusion</p> <p>COX-2 regulates cell cycle transition via EP4 receptor and altered p21^WAF1/CIP1expression. EGFR pathways appear important. Specific targeting of the EP4 receptor or downstream targets may offer a safer alternative to COX-2 inhibition in the chemoprevention of CRC.</p